Learn subject-verb agreement by mastering these simple, jargon-free rules.
1. When a sentence begins with here or there, reverse the sentence to get the verb right.
Here (is, are) your luggage.
Your luggage is here.
There (go, goes) my two best friends.
My two best friends go there.
Here (come, comes) the bride.
The bride comes here.
There (seem, seems) to be many possibilities.
Many possibilities seem to be there.
2. Don’t be fooled by numbers. A unit of time or measurement is always singular.
Twenty minutes is the average length of a doctor’s appointment. (unit of time – singular)
Twenty students are waiting impatiently for the bell to ring. (twenty separate people – plural)
Two bananas are left in the bowl on the table. (two separate bananas – plural)
Two days is barely enough time to catch up on my chores during the weekend. (unit of time – singular)
Three yards of material is more than enough for this dress. (unit of measurement – singular)
Three homes in our neighborhood are beautifully landscaped. (three separate homes – plural)
3. In either/or, neither/nor sentences, use the words near or/nor to choose your verb.
Neither my sisters nor my mother likes Chinese food.
Neither my mother nor my sisters like Chinese food.
Either John or his parents take Aunt Eleanor out to eat every weekend.
Either his parents or John takes Aunt Eleanor out to eat every weekend.
4. Remember that prepositions (in, by, for, with, to, of) introduce phrases that must be crossed out before you choose the verb.
One of the classrooms is empty. (skip “of the classrooms”)
The box on the top shelf is heavy. (skip “on the top shelf”)
The children in the third grade are going on a trip today. (skip “in the third grade”)
5. Words like each, every, any, one, body are always singular.
Each of the students brings a bag lunch every day. (“Each” means “Each one”)
Every student brings a bag lunch every day. (Notice that “student” is singular)
Everyone from both schools is here. (Look for the word “one” in “everyone”)
Notice that “somebody” has the singular word “body”–so does “anybody”
6. Be especially careful with sentences that have two subjects and two verbs. (The phrase “one of” is often a good clue to take a closer look.)
Compare these sentences:
Mary is a woman who has an advanced degree. (a woman has)
Mary is one of the women who have advanced degrees. (many women have)
Sherman is a physician who listens intently to his patients. (a physician listens)
Sherman is one of those physicians who listen intently to their patients. (those physicians listen)
I think you should also cover some areas of usage that vary depending on which side of the pond you live. For example, collective nouns tend to have a plural verb in British English, whereas they usually agree with a singular verb in American English.
For example, in the following British piece of news (http://www.ibtimes.co.uk/articles/327718/20120413/boris-johnson-tech-city-jobs.htm)we find the following words: (it is interesting to note that the government can be replaced by ‘it’):
When asked by the IBTimes UK if he felt the government were doing enough to support London in developing this potential, Johnson indicated it could be doing more and that City Hall was lobbying for change.
However, an American article on a completely different topic includes the following:
The federal government’s brief offered a startling description of what the government was doing on the Arizona-Mexico border in the spring of 2010.
I have the impression that in present times the above differentiation is becoming blurrier and blurrier. However, much like with the case of ‘whom’, it is worth mentioning.