LET Elementary English — Writing in the DisciplineRevision Notes

Exam Tips

• In 'delete a sentence for unity' items: read the topic sentence first, then check every other sentence. The one that does NOT directly support the controlling idea is the answer.
• For topic-sentence identification items: look for the sentence that is broad enough to be developed but specific enough to guide the paragraph.
• Remember: a topic sentence controls ONE paragraph; a thesis statement controls an ENTIRE essay.
• In paragraph-arrangement (scrambled sentences) items: find the topic sentence first — it is almost always the first sentence in the correct order.

Key Points

• A paragraph is a group of sentences that develops ONE main idea. Every sentence must relate to that single controlling idea.
• A well-written paragraph has FOUR qualities the LET tests directly: Unity, Coherence, Adequate Development, and Emphasis.
• UNITY means every sentence supports one controlling idea. The classic LET item gives a paragraph and asks which sentence should be DELETED because it destroys unity. The answer is always the off-topic sentence.
• COHERENCE means sentences flow logically and are clearly connected. The reader moves easily from one idea to the next.
• ADEQUATE DEVELOPMENT means the main idea is supported by enough specific details, examples, facts, or reasons. A paragraph that is too short is underdeveloped.
• EMPHASIS means the most important idea is given appropriate prominence, usually through its position (beginning or end of the paragraph).
• The TOPIC SENTENCE states the paragraph's main idea and controls its content. It most commonly appears FIRST in the paragraph.
• The topic sentence may also appear LAST as a summarizing statement (inductive paragraph) or be IMPLIED (the reader must infer it).
• A good topic sentence is neither too broad (impossible to cover) nor too narrow (a mere fact with nothing to develop).
• SUPPORTING SENTENCES explain, illustrate, or prove the topic sentence with specific details, examples, or evidence.
• A CLINCHER or CONCLUDING SENTENCE may close the paragraph by reinforcing or summarizing the main idea.

Definitions

Section Title

The Paragraph: The Basic Unit of Composition

Common Mistakes

• Confusing the topic sentence (controls ONE paragraph) with the thesis statement (controls the WHOLE essay). These are distinct concepts the LET loves to test.
• Choosing a topic sentence that is too broad — for example, 'Education is important' cannot be fully developed in one paragraph.
• Choosing a topic sentence that is too narrow — for example, 'The Philippines has 7,641 islands' is a single fact, not a controlling idea.
• Missing the off-topic sentence in a unity item because it is loosely related to the topic but does not directly support the controlling idea.
• Placing the topic sentence last and then labeling the paragraph as lacking a topic sentence — it has one, just in the inductive position.

Exam Tips

• The LET blank-transition item: read the sentence BEFORE the blank AND the sentence AFTER the blank. Identify the logical relationship (addition? contrast? result?) THEN choose the matching transition.
• Quick cheat: 'however' = contrast, 'therefore/thus/consequently' = result, 'moreover/furthermore/in addition' = addition, 'for example/for instance' = illustration, 'finally' = last in a sequence.
• In scrambled-sentence items: (1) find the topic sentence, (2) find the clincher, (3) arrange the supporting sentences logically using signal words as clues.
• Parallel structure items: check that all items in a list use the SAME grammatical form (all nouns, all gerunds, all infinitives, etc.).

Key Points

• COHERENCE is the logical and sensible flow of ideas — the 'big picture' organization of a text.
• COHESION is the grammatical and lexical 'glue' that links sentences at the surface level — the visible connectors.
• Both coherence and cohesion work together. A text can be cohesive (uses many connectors) but still incoherent (ideas are illogical).
• TRANSITIONAL EXPRESSIONS (signal words) are the most frequently tested cohesion device on the LET. Always match the transition to the LOGICAL RELATIONSHIP between the two ideas.
• ADDITION transitions: also, moreover, in addition, furthermore, besides
• CONTRAST transitions: however, on the other hand, nevertheless, in contrast, yet, but
• CAUSE AND EFFECT transitions: therefore, consequently, as a result, thus, hence
• EXAMPLE transitions: for instance, for example, such as, to illustrate
• SEQUENCE transitions: first, next, then, after that, finally, subsequently
• CONCLUSION transitions: in conclusion, in summary, to sum up, therefore
• Other cohesion devices: repetition of key terms, synonyms, pronoun reference, parallel structure.
• LOGICAL ORDER types: chronological (time order), spatial (space/location), order of importance (least to most or most to least), general to specific (deductive) or specific to general (inductive).
• PRONOUN REFERENCE must be clear — each pronoun must point unambiguously to a specific noun earlier in the text.
• PARALLEL STRUCTURE in related sentences and in lists creates both cohesion and grammatical correctness.

Definitions

Section Title

Coherence and Cohesion: The Glue of Good Writing

Common Mistakes

• Choosing a transition that SOUNDS right without checking whether its meaning matches the relationship. Always read BOTH sentences before selecting.
• Confusing 'however' (contrast) with 'therefore' (cause-effect). These are opposites in meaning.
• Using 'furthermore' or 'moreover' when the second sentence actually CONTRASTS the first — these signal addition, not contrast.
• Forgetting that 'thus,' 'hence,' and 'consequently' all signal cause-effect (result), not contrast.
• Confusing coherence (logical flow of ideas) with cohesion (surface connectors). You need BOTH for a well-written text.

Exam Tips

• To identify the BEST thesis in a four-option LET item: eliminate options that are (a) plain facts, (b) vague announcements, or (c) too broad. The correct thesis is specific, arguable, and previews the body paragraphs.
• Remember the formula: Thesis = Topic + Specific Claim + Reasons/Preview. Example: 'School uniforms [topic] should be mandatory [claim] because they reduce peer pressure and promote equality [preview of reasons].'
• A thesis is to an essay what a topic sentence is to a paragraph — same function, different scope.
• For conclusion items: the correct answer will restate the thesis (not copy it word for word) and summarize — NOT introduce new ideas.

Key Points

• An ESSAY develops ONE central idea across MULTIPLE paragraphs, organized into three parts: Introduction, Body, and Conclusion.
• INTRODUCTION: engages the reader (hook), gives context/background, and ends with the THESIS STATEMENT.
• BODY: several paragraphs, each with its own topic sentence supporting the thesis, arranged in logical order and linked by transitions.
• CONCLUSION: restates the thesis in fresh words, summarizes main points, and closes with a final thought. It must NOT introduce new arguments.
• The THESIS STATEMENT is the central claim of the whole essay — usually ONE sentence near the end of the introduction.
• A strong thesis is: (1) FOCUSED and SPECIFIC — not a broad announcement; (2) ARGUABLE or ASSERTIVE — expresses a stand, not a plain fact; (3) A GUIDE to the essay's structure — previews the main supporting points.
• WEAK thesis (announcement): 'This essay will discuss school uniforms.' — This is NOT a thesis; it is merely a topic announcement.
• WEAK thesis (plain fact): 'The Philippines requires school uniforms in public schools.' — This is a fact, not a position.
• STRONG thesis: 'School uniforms should be required in all public elementary schools because they reduce distraction, promote equality, and foster school pride.' — Specific, arguable, previews three body paragraphs.
• The LET asks you to IDENTIFY the best thesis among four options, DISTINGUISH a thesis from a topic or fact, and DIFFERENTIATE a thesis (whole essay) from a topic sentence (single paragraph).
• The conclusion must NOT introduce new ideas or arguments — a common LET distractor option.

Definitions

Section Title

The Essay and the Thesis Statement

Common Mistakes

• Confusing the TOPIC SENTENCE (controls one paragraph) with the THESIS STATEMENT (controls the whole essay). This is one of the most common LET errors.
• Selecting a plain fact as a thesis. A thesis must express a POSITION or CLAIM that can be argued, not a commonly known fact.
• Selecting a vague or overly broad statement as a thesis. 'Education is important for society' is too broad to be a good thesis.
• Thinking the conclusion introduces new arguments. The LET will offer a distractor that says a good conclusion adds new points — it does NOT.
• Placing the thesis at the very first sentence of the introduction. The thesis typically comes at the END of the introductory paragraph, after the hook and background.

Exam Tips

• Identify the mode by asking: Does it TELL A STORY (narration)? PAINT A PICTURE (description)? EXPLAIN or INFORM (exposition)? TAKE A STAND and CONVINCE (argumentation)?
• The word 'because' used to support a claim signals argumentation. Sequential steps signal exposition (process). A claim that asks you to agree signals persuasion/argumentation.
• If a passage uses a clear THESIS and supporting ARGUMENTS WITH EVIDENCE, it is argumentative even if it also explains.
• Process writing (e.g., the DepEd classroom observation process, steps in lesson planning) is always classified as EXPOSITORY.

Key Points

• The LET uses the FOUR TRADITIONAL MODES OF DISCOURSE as a framework for understanding writing types.
• NARRATION: tells a story or recounts events, usually in CHRONOLOGICAL ORDER. Uses time-order transitions (first, then, next, finally). Example: a personal narrative, a historical account.
• DESCRIPTION: creates a vivid SENSORY picture of a person, place, or thing. Usually organized in SPATIAL ORDER (top to bottom, near to far, left to right). Uses vivid adjectives and imagery.
• EXPOSITION: EXPLAINS, INFORMS, or DEFINES. This is the most common mode in academic and professional writing. Sub-types include: process writing, comparison-contrast, cause-and-effect, classification, and definition.
• ARGUMENTATION/PERSUASION: takes a POSITION and supports it with REASONS AND EVIDENCE to convince the reader. Includes a thesis/claim, supporting arguments, and acknowledgment/refutation of the opposing view.
• Most academic writing (including research papers, lesson plan rationales, and DepEd reports) is EXPOSITORY.
• On the LET, items may describe a passage and ask you to identify its mode, or give you a writing task and ask which mode is most appropriate.
• Narration and description are often combined; argumentation and exposition often overlap in academic writing.

Definitions

Section Title

Types of Writing (Modes of Discourse)

Common Mistakes

• Confusing ARGUMENTATION with PERSUASION — argumentation relies on logic and evidence; persuasion may use emotional appeals. On most LET items they are treated as one mode.
• Labeling a 'how-to' or process piece as narration instead of exposition. A process essay (e.g., 'How to write a lesson plan') is EXPOSITORY, not narrative, even though it uses sequence.
• Forgetting that most academic writing — including research papers, book reports, and DepEd narrative reports — is EXPOSITORY.
• Thinking description is only about nature scenes — description also applies to people, objects, emotions, and processes.

Exam Tips

• Apply this rule: If the LET item describes a change to IDEAS, STRUCTURE, or ORGANIZATION → REVISING. If it describes fixing GRAMMAR, SPELLING, or PUNCTUATION → EDITING.
• Example: 'Maria added two more supporting details to her third paragraph.' → REVISING (content). 'Maria changed its to it's in her conclusion.' → EDITING (mechanics).
• Remember the order: Prewriting → Drafting → Revising → Editing → Publishing. Use the mnemonic: 'Pretty Dogs Run Everywhere Proudly.'
• Brainstorming, clustering, freewriting, and outlining all belong to PREWRITING — know all four techniques.

Key Points

• The writing process is taught and tested as a STAGED, RECURSIVE process with five main stages.
• Stage 1 — PREWRITING: generating and planning ideas. Techniques include brainstorming, freewriting, clustering/concept mapping, and outlining. This stage includes narrowing the topic and identifying purpose and audience.
• Stage 2 — DRAFTING: writing the first full version. Prioritize getting ideas down; polish comes later.
• Stage 3 — REVISING: re-examining the draft at the level of CONTENT and ORGANIZATION. Tasks: sharpening the thesis, reordering paragraphs, adding or cutting support, improving transitions. This is NOT about fixing grammar.
• Stage 4 — EDITING AND PROOFREADING: correcting GRAMMAR, SPELLING, PUNCTUATION, and MECHANICS. This is the surface-level stage.
• Stage 5 — PUBLISHING: sharing the finished work with its intended audience.
• KEY DISTINCTION (frequently tested): REVISING = content and organization (ideas, structure). EDITING = surface errors (grammar, mechanics).
• The LET will describe a specific change (e.g., 'the writer moved the second paragraph before the first') and ask which stage it belongs to. Moving paragraphs = REVISING. Correcting a comma splice = EDITING.
• The process is RECURSIVE — writers may move back and forth between stages, especially between drafting and revising.
• Knowing the writing process is also relevant to your teaching practice, as DepEd's K–12 curriculum uses a process-oriented approach to teaching writing in Mother Tongue, Filipino, and English.

Definitions

Section Title

The Writing Process

Common Mistakes

• Saying that correcting a comma splice happens during REVISING — it is EDITING because it is a surface-level grammar correction.
• Saying that rewriting an introduction happens during EDITING — rewriting for clarity and organization is REVISING.
• Thinking the writing process is strictly linear. It is RECURSIVE — writers regularly loop back to earlier stages.
• Forgetting that PREWRITING includes outlining and audience/purpose analysis, not just brainstorming.

Exam Tips

• To classify a sentence: first count the number of independent clauses, then check for dependent clauses. Simple (1 IC, 0 DC), Compound (2+ IC, 0 DC), Complex (1 IC, 1+ DC), Compound-Complex (2+ IC, 1+ DC).
• FANBOYS test: if the conjunction is For, And, Nor, But, Or, Yet, or So → it joins EQUAL (coordinate) clauses → COMPOUND. If the conjunction is because, when, although, if, since, etc. → it introduces a DEPENDENT clause → COMPLEX.
• Comma splice fix options: (1) use a semicolon, (2) add a coordinating conjunction after the comma, (3) make them two separate sentences.
• In 'best sentence' items, the correct answer is usually the one that is clear, concise, avoids redundancy, and maintains parallel structure.

Key Points

• Sentences are classified by STRUCTURE (how many clauses they contain) and by PURPOSE (what they do).
• BY STRUCTURE — SIMPLE sentence: ONE independent clause. Example: 'The teacher distributed the activity sheets.'
• BY STRUCTURE — COMPOUND sentence: TWO or more independent clauses joined by a coordinating conjunction (FANBOYS: For, And, Nor, But, Or, Yet, So) OR a semicolon. Example: 'The bell rang, and the pupils lined up.'
• BY STRUCTURE — COMPLEX sentence: ONE independent clause + at LEAST ONE dependent clause (subordinate clause). Example: 'When the bell rang, the pupils lined up.'
• BY STRUCTURE — COMPOUND-COMPLEX sentence: at LEAST TWO independent clauses + at LEAST ONE dependent clause. Example: 'When the bell rang, the pupils lined up, and the teacher closed the door.'
• BY PURPOSE — DECLARATIVE: makes a statement; ends with a PERIOD.
• BY PURPOSE — INTERROGATIVE: asks a question; ends with a QUESTION MARK.
• BY PURPOSE — IMPERATIVE: gives a command or request; subject 'you' is understood; ends with a PERIOD or exclamation point.
• BY PURPOSE — EXCLAMATORY: expresses strong feeling; ends with an EXCLAMATION POINT.
• MATURE academic prose uses a VARIETY of sentence structures — LET improvement items typically reward the clearer, more concise, and grammatically parallel version.
• A COMMA SPLICE is an ERROR: two independent clauses joined by ONLY a comma. Fix it with a semicolon, or a comma + coordinating conjunction, or a period.

Definitions

Section Title

Sentence Structure and Variety

Common Mistakes

• Confusing a COMPOUND sentence (joined by 'and') with a COMPLEX sentence (joined by 'when,' 'because,' 'although,' etc.).
• Thinking a COMPLEX sentence is longer or more advanced than a compound sentence. Length is not the criterion — the TYPE of clause determines the classification.
• Creating a comma splice by joining two independent clauses with only a comma. This is among the most common writing errors.
• Forgetting that an IMPERATIVE sentence has an implied subject 'you' — it is not a fragment even though no subject appears.

Exam Tips

• It's vs. Its: substitute 'it is' — if the sentence still makes sense, use 'it's.' If not, use 'its' (possessive).
• For capitalization items: ask 'Is this a SPECIFIC, UNIQUE name?' If yes → capitalize (proper noun). If it is a general category → do NOT capitalize (common noun). Example: 'elementary school teacher' (common) vs. 'DepEd Secretary' before a name (title + name → capitalize).
• For comma items: check if the clause is ESSENTIAL (no comma) or NON-ESSENTIAL (use commas to set it off). Essential clauses use 'that'; non-essential use 'which.'
• Colon after a complete sentence, semicolon between two independent clauses WITHOUT a conjunction — these are the two most-tested punctuation distinctions.
• For spelling, memorize the exceptions: 'weird,' 'seize,' 'either,' 'leisure' violate 'i before e' and are frequently tested.

Key Points

• MECHANICS are the surface conventions of written English. LET items test mechanics through error items and 'correctly written sentence' items.
• CAPITALIZATION RULES: (1) First word of every sentence. (2) The pronoun 'I'. (3) Proper nouns and proper adjectives — names of specific people (Maria Santos), specific places (Batangas), nationalities (Filipino), languages (Tagalog), days (Monday), months (January), holidays (Araw ng Kalayaan), and historical events (People Power Revolution). (4) Titles of honor BEFORE a name (President Marcos, Teacher Ana, Dr. Reyes). (5) Important words in titles of works (The Noli Me Tangere).
• Do NOT capitalize: common nouns (teacher, city, river), seasons (summer, rainy season), titles used WITHOUT a name (the president, our teacher).
• COMMA rules: (1) Separates items in a series. (2) Sets off introductory elements. (3) Sets off nonessential (nonrestrictive) clauses and phrases. (4) Precedes a coordinating conjunction joining two INDEPENDENT CLAUSES. (5) Sets off direct address. (6) Sets off appositives.
• SEMICOLON: joins two closely related INDEPENDENT CLAUSES without a conjunction; also separates series items that already contain commas.
• COLON: introduces a list, an explanation, or a formal quotation after a COMPLETE sentence; follows the SALUTATION of a BUSINESS letter (Dear Sir:).
• APOSTROPHE: shows POSSESSION (teacher's book, teachers' lounge); marks CONTRACTIONS (it's = it is). NEVER use for a simple plural (pupils NOT pupil's when meaning more than one).
• QUOTATION MARKS: enclose direct speech and titles of SHORT WORKS (articles, poems, short stories, songs). Titles of long works (books, newspapers, films) are ITALICIZED (or underlined in handwriting).
• SPELLING KEY RULES: 'i before e except after c' (believe, receive); double the final consonant before a vowel suffix if the vowel is short and stressed (stop → stopping); drop the silent 'e' before a vowel suffix (write → writing); change 'y' to 'i' before most suffixes (happy → happiness).
• Commonly misspelled words tested on the LET: accommodate, separate, occurrence, definitely, necessary, privilege, Caribbean, recommendation, harassment, embarrass.

Definitions

Section Title

Mechanics: Capitalization, Punctuation, and Spelling

Common Mistakes

• Using an apostrophe for a simple plural: 'The pupil's raised their hands' (WRONG) vs. 'The pupils raised their hands' (CORRECT).
• Confusing 'it's' (it is) with 'its' (possessive): 'The school held its program' (possessive, no apostrophe). 'It's a national holiday' (it is, apostrophe needed).
• Not capitalizing the first word of a direct quotation that forms a complete sentence.
• Using a colon after a FRAGMENT (incomplete sentence) to introduce a list — the colon must follow a COMPLETE sentence.
• Capitalizing seasons (summer, winter) — these are COMMON nouns, not proper nouns, and are NOT capitalized.
• Using a comma instead of a colon after the salutation of a BUSINESS letter. Business letters use a colon (Dear Sir:); friendly letters use a comma (Dear Ana,).

Exam Tips

• Memorize the SEVEN PARTS of a business letter in order: Heading → Inside Address → Salutation (colon) → Body → Complimentary Close (comma) → Signature → Enclosure (if any).
• MEMO vs. LETTER: MEMO = To/From/Date/Subject + body only (no salutation, no close). LETTER = all seven parts including salutation and complimentary close.
• Punctuation after salutation: COLON for business (Dear Sir:) → COMMA for friendly (Dear Ana,). This is a classic LET distractor.
• Punctuation after complimentary close: always a COMMA (Sincerely yours,). NEVER a colon.
• For minutes items: past tense, records decisions and actions, written AFTER the meeting.

Key Points

• Teachers write many official documents in their daily practice — LET tests your knowledge of the PARTS and FORMATS of business letters, memos, and other practical documents.
• BUSINESS LETTER — Seven parts: (1) HEADING (sender's address + date), (2) INSIDE ADDRESS (recipient's name and address), (3) SALUTATION (Dear Sir/Madam: — COLON, not comma), (4) BODY, (5) COMPLIMENTARY CLOSE (Sincerely yours, Respectfully yours, — followed by a COMMA), (6) SIGNATURE (handwritten + printed name), (7) ENCLOSURE NOTATION (Enc. or Enclosure) if documents are attached.
• BLOCK FORMAT: every part is flush LEFT — the most common format in Philippine official correspondence.
• MODIFIED BLOCK FORMAT: heading, complimentary close, and signature are CENTER or RIGHT; the rest is flush left.
• PERSONAL/FRIENDLY LETTER: informal; uses a COMMA after the salutation (Dear Ana,). No inside address required.
• MEMORANDUM (MEMO): internal message with a fixed header: TO, FROM, DATE, SUBJECT (or RE). NO salutation, NO complimentary close. Body is concise and direct. Used for internal school communications (e.g., teacher to principal).
• MINUTES OF A MEETING: official record of what was discussed and decided, written AFTER the meeting in the PAST TENSE. Includes: meeting title, date/time/place, members present, agenda items discussed, resolutions/decisions, and adjournment.
• RÉSUMÉ: summarizes qualifications, education, and work experience. Accompanied by an APPLICATION (COVER) LETTER — a formal business letter stating the position sought.
• REPORT: presents findings in an organized, often headed structure. Academic reports may include: title page, abstract, introduction, body, conclusion, and references.
• ABSTRACT: a brief summary (usually 100–250 words) of a longer work (research paper, report). It captures the purpose, method, findings, and conclusion.
• Properties of well-written text (Philippine K–12 framework): ORGANIZATION, COHERENCE AND COHESION, LANGUAGE USE, and MECHANICS.

Definitions

Section Title

Practical and Correspondence Writing

Common Mistakes

• Using a COMMA after the salutation of a BUSINESS letter. Business letters use a COLON (Dear Principal Reyes:). A COMMA is used in FRIENDLY/PERSONAL letters (Dear Ate Ana,).
• Including a salutation in a MEMO. Memos go directly from the header (To/From/Date/Subject) to the body — no 'Dear' greeting.
• Placing the INSIDE ADDRESS after the salutation. The inside address always comes BEFORE the salutation in a business letter.
• Writing the CONCLUSION of the memo or letter FIRST in the heading. The HEADING contains the SENDER's address and date, not the recipient's.
• Writing minutes of a meeting in the PRESENT TENSE. Minutes are always in the PAST TENSE ('The principal reported…' not 'The principal reports…').

Exam Tips

• For 'best sentence for an academic paper' items: eliminate the option with contractions, slang, or vague words. The correct answer is formal, precise, and objective.
• Quick test for formality: Can you replace the word with a more precise synonym? If the word is vague or conversational, it is informal.
• Remember: register is about APPROPRIATENESS — a friendly letter using informal language is NOT wrong; it is contextually correct.
• In formal academic writing: prefer 'research indicates' over 'research shows,' 'children' over 'kids,' 'significant' over 'a lot of.'

Key Points

• REGISTER refers to the level of formality in language, determined by the audience, purpose, and context of writing.
• FORMAL REGISTER (academic/professional writing): No contractions (use 'do not,' not 'don't'), no slang or text-speak, precise vocabulary (use 'many' not 'a lot of'), objective third-person stance, arguments based on evidence, passive voice used when appropriate.
• INFORMAL REGISTER (friendly letters, blog posts, personal narratives): Contractions are acceptable, conversational tone, first-person perspective, colloquial expressions.
• The LET may present four sentences and ask which is MOST APPROPRIATE for an academic paper. The correct choice is FORMAL, SPECIFIC, and FREE OF COLLOQUIALISMS.
• Appropriateness is judged against AUDIENCE AND PURPOSE — a friendly letter legitimately uses informal register. This is not a flaw; it is APPROPRIATE to its context.
• Academic writing uses THIRD PERSON (the researcher, the teacher, pupils) rather than first person (I, we) in formal reports.
• VAGUE LANGUAGE is inappropriate in academic writing: avoid 'a lot of,' 'stuff,' 'things,' 'very,' 'nice,' 'got.' Use precise, specific vocabulary instead.
• HEDGE LANGUAGE is appropriate in academic writing to qualify claims: 'The data suggest…' 'It appears that…' 'Research indicates…'
• Sentence-level formality: complete sentences are required; fragments and run-ons are unacceptable in academic prose.

Definitions

Section Title

Formal Register in Academic Writing

Common Mistakes

• Using contractions (it's, don't, can't) in formal academic writing. Contractions are inappropriate in formal register.
• Using 'a lot of' instead of 'many,' 'much,' or 'a great number of' in academic writing.
• Using first-person 'I' in a formal research report when third-person is required.
• Thinking informal register is always wrong. It is APPROPRIATE for friendly letters, personal narratives, and blogs — the standard is appropriateness to audience and purpose, not universal formality.