Grammar is all about words and their arrangement. It is about the rules relating to these things so that we can communicate in such a way that we can understand each other, and not act in a way that was never intended by the other party, be it a family member, a work colleague, or a friend. In the workplace, for example, poor grammar and consequent misunderstandings can be costly in terms of time and money.

I’ve picked out a lot of pairs of words that often cause problems, as well as other issues (such as its and it’s, and which and that). Many of the pairs are words that are close in spelling or meaning but are not used in the same way. It’s useful to use a mnemonic (memory jogger) to help you remember which one to use. I have included a few. Often it’s best to make up your own mnemonic for any you have trouble with.

– accept or except: Examples: I accept your invitation. We’re all here except John. Think of John as the exception to the rule.

– adapt or adopt: Adapt is about changing or adjusting; adopt means to take something up. Examples: We will need to adapt to our new surroundings. The Government adopted the report.

– adverse or averse: Adverse is antagonistic or opposing; averse is disinclined or reluctant. Example: He was averse to adverse criticism.

– advice or advise: Advice is a noun; advise is a verb. Examples: They accepted our advice. I will advise you of the outcome. You could think of ice (as in advice) as a noun.

– affect or effect: Affect is a verb and means to act on or produce a change; effect as a verb means to bring about. It can also be a noun. Examples: The new migration policy will affect the rate of population growth. We will effect (verb) the changes as soon as possible. The effect (noun) of the changes will be significant.

– aid or aide: To aid is to help; an aide is an assistant. Examples: He went to aid the injured person. The aide set up the classroom before the lesson.

– allude or elude: Allude means making a passing or casual reference; elude is to escape or avoid. Examples: She alluded to her previous job. He tried to elude the police.

– alternate or alternative: Alternate means every other; alternative means a choice of two things. Examples: We propose to hold a branch meeting on alternate weeks. The alternative to flying to Australia is to go by sea.

– ambiguity: It’s very easy to write an ambiguous sentence. One thing to do when checking your work is to read each sentence and ask yourself: Can this sentence be interpreted in more than one way? Try and reword or rearrange the sentence so that it can only have one meaning. Sometimes it could be as simple as adding or deleting a comma.

– among or between: Among is usually preferred if three or more persons or things are involved and between if only two are involved, although between is becoming more common for three or more persons or things.

– apostrophes: Many people have trouble with apostrophes. An apostrophe goes before the s for singular and after the s for plurals. Example: the judge’s comments, if one judge; the judges’ comments, if two or more judges. If a word is already plural, the apostrophe goes before the s. Example: children’s toys. No apostrophe is used for plurals when the possessive case isn’t used. Examples: back in the 1970s; apples for sale. When to use its and it’s is covered later.

– bazaar or bizarre: Bazaar is a marketplace; bizarre means odd or unique. Examples: We’ll meet at the bazaar. She worried about his bizarre behavior.

– biannual or biennial: Biannual means twice a year, whereas biennial means every two years. In general, avoid these words as readers tend to confuse them. Instead, use twice a year or semiannual, and every two years, respectively. Similarly, readers may be confused by words such as biweekly and bimonthly. However, bicentennial should present no problems.

– bought or brought: Bought means purchased; brought means to take along or cause to come. Examples: I bought the videos yesterday. She brought her lunch with her.

– breath or breathe: Breath is the noun; breathe is the verb. Examples: She held her breath waiting for a reply. He could breathe freely again.

– cite or site or sight: Cite means to quote, refer to, or mention in support; site (as a verb) means to locate or place something; sight (as a verb) means to see something. Examples: He cited a paragraph from the journal article in his report. The rubbish bin was sited near the picnic table. The document was sighted as part of the audit process.

– comma splice: This is where a comma joins two separate sentences without using a conjunction. Example: The availability of childcare has increased, this enables more women to work full-time. Options to fix this include: The availability of childcare has increased and this enables more women to work full-time. The availability of childcare has increased, enabling more women to work full-time. The greater availability of childcare has enabled more women to work full-time. Other options would be to have two separate sentences or to use a semicolon instead of a comma. None of the five is incorrect, although the second or third options might be preferred.

– comparative and superlative: Certain adjectives can have comparative (two) and superlative (three or more) forms. You often see a sentence using a superlative, e.g. largest or oldest, when only two things are being compared, in which case use larger or older.

– complement or compliment: Complement is where something goes with another thing to complete it or make it whole; a compliment is an expression of praise or regard. Examples: A tie will complement his shirt. She gave him a compliment on his neat appearance. As a way to remember the difference, in “I give you a compliment”, relate the i in compliment to I at the start.

– dangling modifier: This is where a word or phrase modifies another word or phrase that isn’t clearly stated in the sentence or isn’t in the sentence at all. Example: Driving along the road in the late afternoon, the sun was in my eyes. But the sun doesn’t drive. Solution? Avoid “As I drove …” as “as” can mean either “when” or “because”. Turn it around: The sun was in my eyes when I drove along the road in the late afternoon.

– desert or dessert: Examples: A desert is dry and sparse (and has only one s). I love dessert and want more (think of the second s as a second serve).

– discreet or discrete: Discreet means being careful to avoid mistakes or not saying something carelessly; discrete refers to something detached or separate. Examples: They were discreet in their business dealings. The new project was regarded as discrete from other projects.

– disinterested or uninterested: Disinterested is where you have no personal involvement or bias; uninterested is being indifferent or not concerned. Examples: The umpire was disinterested in the outcome of the match. She is uninterested in him.

– eminent or imminent: Eminent means outstanding, prominent or distinguished; imminent means likely to occur at any moment. Examples: An eminent lawyer died in a car crash. Retrenchments from many departments were imminent.

– empathy or sympathy: Empathy is about feelings or being able to have the same feelings as someone else; sympathy is about actions such as saying sorry.

– foreword or forward: I have seen Forward used at the start of draft publications several times. It should of course be Foreword. Break it up and think of it as a fore word to the rest of the document.

– formally or formerly: Formally is to do with abiding by conventions; formerly means previously. Examples: She was formally accepted into the club. He was formerly a company director.

– good or well: Basically, good is an adjective and describes a noun; well is an adverb and describes a verb. Examples: I read a good book over the weekend. She doesn’t speak English well. But well can also be an adjective. Examples: I am well. He is not a well person. Be careful with a sentence like “I am good”. If it follows something like: “How are you?”, then it’s fine. But if it’s somewhat by itself, “I am good” can be construed as “I am behaving”.

– historic or historical: Historic means memorable, or likely to be famous in history; historical means having actually happened or existed. Examples: The opening of the new convention centre was a historic occasion for the city. The book gives an account of various historical events since the founding of the state.

– I or me: Use “I” in the subject of a sentence and “me” in the object. Examples: John and I wrote the report last week. He handed the report to Sarah and me last week. Some people want to write “Sarah and I” in the last example. If two people are referred to together in a sentence, determine which pronoun to use by crossing out the words next to the pronoun. In the above examples, omit the words “John and” and “Sarah and” respectively. It’s then easy to see whether to use I or me. You wouldn’t say: “Me wrote the report last week” or “He handed the report to I last week”.

– its or it’s: The possessive case uses no apostrophe. Example: The town is well known for its hospitality. However, the contracted form takes an apostrophe. Example: I think it’s going to rain. Before using an apostrophe in “its”, check to see if it can be expanded to “it is” or “it has”. If so, then use an apostrophe. If not, then no apostrophe is used. Think of the apostrophe as a shrunken down “i” in “ït is”(or “ha” in “it has”). If you can’t write it out as “it is” (or “it has”), there’s no apostrophe. There is no such word as its’, that is, with apostrophe after the s.

– lay or lie: To lie is to move into a reclining position; to lay is to put someone or something somewhere. Examples: I lie down when I’m tired. I lay the baby in her cot when she’s tired. Also note the following examples: I am lying down because I feel sick. I am laying my clothes out on the bed. The past tense of lie is lay. Example: I lay on the couch yesterday afternoon. The past tense of lay (as in laying the baby down) is laid. Examples using past participles: I have lain on the couch three evenings this week. I have laid out my clothes ready to pack.

– loose or lose. Think of a loose moose! For lose, as in “You’ll lose money”, think of lose and money as both having a single o.

– parallel structure: Use parallel structure when listing items in a sentence as it makes it easier to understand and can avoid possible ambiguity. Example: I like tennis, basketball, and ride my bike. This is faulty parallelism. Correct parallelism would be: I like tennis, basketball and to ride my bike (or bike riding).

– passed or past: Passed is the past tense of pass. Past can be a noun, adjective, adverb or preposition. Note the following examples: She passed all her exams. History is a study of the past (noun). The office has been busy in the past (adjective) month. The procession went past (adverb) the town hall. They bought the old house past (preposition) the church.

– principal or principle: A principle is a rule (both words end in le). The principal is your pal (both have pal). Principal means main (both words contain the same vowels – a and i).

– run-on sentence: This is where two sentences are joined as one. Example: The meeting was cancelled only two people were available. Add “because” or “when” or “as” after “cancelled”. Or you could make it two sentences, or use a semicolon after “cancelled”, but better to add a conjunction as above.

– sentence fragment: This is where you have a string of words that you mean to be a sentence but actually isn’t one. Example: Three people walking down the street. Don’t rely on a computerized grammar check; it doesn’t always get it right by any means. As a minimum, a sentence usually needs a subject and a verb. Example: It stinks.

– stationary or stationery: Stationary means standing still (first and third words both have “a”). Stationery includes pens, pencils, paper, and envelopes (look at all the e’s). A stationer sells stationery (more e’s).

– tenses: It’s usually better to stick with the same tense throughout a document or article rather than jumping from past to present and back again.

– that or which: Use “that” or “which” to start a clause that is an essential part of a sentence. Use “which” to start a non-restrictive or non-defining clause, that is, a clause that is not essential to the meaning of a sentence (note the comma before “which” in the second example below). Examples: The boats that (or which) broke from their moorings during the storm were damaged (that is, only those boats that broke from their moorings were damaged). The boats, which broke from their moorings during the storm, were damaged (that is, all the boats broke from their moorings and were damaged). Where “that” and “which” are interchangeable, use “that” to avoid possible confusion, or the reader might think you’ve left out a comma (or put one in) by mistake. Also, “that” is used for people and things, “which” for things only and “who” for people. Overall, if in doubt, use “which” rather than “that”.

– their or there or they’re: “Their” is the possessive form of “they”. Example: They put their clothes in the washing basket. “There” refers to place or can be used in various other contexts. Examples: We will stay there tonight. There are seven days in a week. There they go again. The word “they’re” is a contraction of “they are”. Example: They’re coming this way. Not: There coming this way.

– verses or versus: Verses are parts of a poem or song; versus means against and is used to denote a sports contest or in law to indicate an action by one party against another.

– who or whom: Writers sometimes use who when they mean whom. Both are pronouns; who is the subjective case whereas whom is the objective case. Examples: Who is going to win this match? (who is the subject). The players, all of whom are contracted, will stay with the team (object). John is the person who got the job (subject; he got the job). This is the man whom I met last night (object; I met him last night).

– whose or who’s: Whose means belonging. Example: Whose house is this? The word who’s is a contraction of “who is” or “who has”.

– your or you’re: “Your” is the possessive form of “you”. Example: Your books are on the table. “You’re” is a contraction of “you are”.