1. Subject and verb agreement
A singular subject takes a singular verb, a plural subject takes a plural verb. The trap is a long phrase between the two: find the real subject first. “The list of names is long”, because the subject is “list”, not “names”.
The quality of the photos are excellent.
The quality of the photos is excellent.
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2. “A” or “an”
The choice depends on the sound, not the letter. Use an before a vowel sound (“an hour”, “an MBA”) and a before a consonant sound (“a university”, “a one-time offer”).
She waited for a hour at an university.
She waited for an hour at a university.
3. “Could of” instead of “could have”
Spoken quickly, “could’ve” sounds like “could of”, but the correct form is always could have, should have, would have, must have.
We should of left earlier.
We should have left earlier.
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4. Apostrophes in plurals
An apostrophe never makes a word plural. Write “two coffees”, “the 1990s”, “CDs”. The apostrophe marks possession (“the client’s order”) or a missing letter (“don’t”).
Fresh apple's and banana's for sale.
Fresh apples and bananas for sale.
5. Comma splices
Two complete sentences cannot be joined by a comma alone. Use a period, a semicolon, or a linking word such as “and”, “but” or “so”.
The meeting is over, we can go home.
The meeting is over, so we can go home.
6. “Fewer” or “less”
Use fewer with things you can count (“fewer emails”, “fewer people”) and less with quantities you cannot count (“less time”, “less water”).
There were less people than last year.
There were fewer people than last year.
7. “Me” or “I”
Remove the other person to find the right pronoun. “Anna and I went out”, because you would say “I went out”. “Between you and me”, because “between” is followed by “me”, “him”, “her”, “us”, “them”.
Me and Anna went to the concert. This stays between you and I.
Anna and I went to the concert. This stays between you and me.
8. “Who” or “whom”
Replace the word with “he” or “him”. If “he” fits, write who; if “him” fits, write whom. In everyday writing, “who” is widely accepted, but after a preposition, “whom” is still expected.
To who should I send the invoice?
To whom should I send the invoice?
9. Dangling modifiers
An opening phrase describes the subject that comes right after the comma. If it does not, the sentence says something absurd.
Walking into the office, the printer was broken again.
Walking into the office, I found the printer broken again.
10. Mixing tenses
Stay in the same tense unless the time actually changes. A story told in the past stays in the past.
She opened the door and sees a letter on the floor.
She opened the door and saw a letter on the floor.
11. Irregular past forms
Some common verbs do not take “-ed”: “bring, brought”, “catch, caught”, “begin, began, begun”, “go, went, gone”. After “have”, use the past participle.
He has went home and brang his laptop.
He has gone home and brought his laptop.
12. Double negatives
In standard English, one negative is enough. “Not” already does the job: follow it with “any”, “anything”, “anyone”, “ever”.
I don't need no help.
I don't need any help.
13. Misplaced “only”
“Only” applies to the word right after it. Place it next to what it limits, or the meaning changes.
I only ate two slices, not three.
I ate only two slices, not three.
14. Capital letters
Days, months, languages, nationalities and the pronoun “I” always take a capital letter in English, unlike seasons (“summer”) and most job titles used alone.
i will call you on monday to talk about the french market.
I will call you on Monday to talk about the French market.
15. Unnecessary commas
Do not put a comma between a subject and its verb, even when the subject is long.
The new version of our app, will be released in June.
The new version of our app will be released in June.
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