English Grammar Guides
Twelve of the most-confused word pairs in English — each fixed in 60 seconds with examples, memory tricks, and a quick practice quiz.
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Affect vs Effect
Affect is almost always a verb meaning 'to influence.' Effect is almost always a noun meaning 'a result.' If you can swap the word for 'influence' (verb), use affect. If you can swap it for 'result' (noun), use effect.
Compliment vs Complement
Compliment (with an i) means praise or a kind remark. Complement (with an e) means something that completes or pairs well with something else.
Further vs Farther
Farther refers to physical, measurable distance. Further refers to figurative or abstract distance, or means 'additional' or 'moreover.'
i.e. vs e.g.
i.e. stands for 'id est' (that is) and introduces a clarification or restatement. e.g. stands for 'exempli gratia' (for example) and introduces one or more examples from a larger set.
Insure vs Ensure
Insure refers to financial insurance — protecting against loss with a policy. Ensure means to make certain or guarantee. Assure (a third option) means to reassure a person.
Into vs In to
Into (one word) is a preposition showing movement, transformation, or location. In to (two words) is just 'in' followed by 'to' — usually when 'to' belongs to an infinitive verb like 'to give' or 'to look.'
Its vs It's
It's (with apostrophe) is a contraction of 'it is' or 'it has.' Its (no apostrophe) is the possessive form of 'it.' If you can replace the word with 'it is' or 'it has,' use it's. Otherwise, use its.
Lay vs Lie
Lay means to place something down — it always takes an object. Lie means to recline or rest — it never takes an object. To make it harder, the past tense of 'lie' is 'lay' — which is why everyone gets confused.
Then vs Than
Then refers to time or sequence ('first this, then that'). Than is used in comparisons ('faster than,' 'more than'). They sound nearly identical but mean completely different things.
To vs Too
To is a preposition ('to the store') or part of an infinitive ('to run'). Too means 'also' or 'excessively' ('too cold,' 'me too'). Two is the number 2. All three sound identical — the spelling is the only signal.
Who vs Whom
Who is the subject of a sentence — it does the action. Whom is the object — it receives the action. The trick: substitute 'he/she/they' (who) or 'him/her/them' (whom). If 'him' works, use 'whom.'
Whose vs Who's
Whose shows possession ('whose book is this?'). Who's is a contraction of 'who is' or 'who has.' If you can substitute 'who is' or 'who has' for the word, use 'who's.' Otherwise, use 'whose.'
Grammar Checker Tools
Paste your text and let our checkers scan for common errors — comma splices, fragments, who/whom mistakes, syllable counts, and more.
Affect or Effect Checker
Free tool that scans your text for every 'affect' and 'effect' and flags likely mistakes. Quick context check with suggestions.
Who or Whom Checker
Free tool that scans your text for every 'who' and 'whom' and flags likely subject/object errors. With context and quick fix suggestions.
Then or Than Checker
Free tool that scans your text for every 'then' and 'than' and flags likely mistakes. Time vs comparison — explained in context.
A or An Checker
Free tool that scans your text for 'a' and 'an' usage. Flags mismatches based on the following word's starting sound, not just its letter.
I or L Checker
Free tool that finds capital I, lowercase l, and the number 1 confusions in your text. Critical for usernames, passwords, and OCR cleanup.
Long or Short Vowel Checker
Free phonics tool that classifies each vowel in your word as long or short. Useful for early readers, ESL learners, and reading teachers.
Fragment or Sentence Checker
Free tool that scans your text and flags sentence fragments — groups of words missing a subject, verb, or complete thought.
Phrase or Clause Checker
Free grammar tool that scans your text and labels each grammatical unit as a phrase or a clause. Useful for grammar homework and editing.
Run-on Sentence Checker
Free run-on sentence checker. Detects sentences that are too long, comma splices, and fused sentences with no punctuation.
Haiku Checker
Free haiku checker. Counts syllables on each line and verifies the traditional 5-7-5 pattern. Visual feedback for over and under counts.
Tanka Checker
Free tanka checker. Counts syllables on each line of your tanka and verifies the traditional 5-7-5-7-7 pattern (31 syllables).
Part-of-Speech & Character Finders
Highlight every noun, verb, adjective, adverb, preposition, or pronoun in your text — plus character-level tools for spotting invisible characters.
Noun Finder
Free noun finder. Paste your text and the tool highlights every noun — proper nouns, common nouns, and noun phrases — with one click.
Verb Finder
Free verb finder. Paste your text and the tool highlights every verb — action verbs, linking verbs, and helping verbs — instantly.
Adjective Finder
Free adjective finder. Paste your text and the tool highlights every adjective — descriptive words that modify nouns.
Adverb Finder
Free adverb finder. Paste your text and the tool highlights every adverb. Great for editing wordy writing — strong verbs beat adverbs.
Preposition Finder
Free preposition finder. Paste your text and highlight every preposition (in, on, at, by, with, for…). Useful for ESL learners.
Pronoun Finder
Free pronoun finder. Highlights personal, possessive, reflexive, demonstrative, and relative pronouns. Useful for grammar lessons and editing.
Character Identifier
Free character identifier. Shows you exactly what every character in your text is — letter, digit, punctuation, emoji, whitespace, or invisible character.
Invisible Character Detector
Free invisible character detector. Finds zero-width spaces, BOMs, RTL marks, and other hidden characters that break copy-paste and validation.