The subject and verb must agree in number: both must be singular, or both must be plural. Problems occur in the present tense because one must add an -s or -es at the end of the verb when the subjects or the entity performing the action is a singular third person: he, she, it, or words for which these pronouns could substitute.Students have problems with subject verb agreement when the verb is a form of be or, have or when the verb is in present tense.
1. The indefinite pronouns anyone, everyone, someone, no one, nobody are always singular and, therefore, require singular verbs.
2. ome indefinite pronouns are particularly troublesome Everyone and everybody (listed above, also) certainly feel like more than one person and, therefore, students are sometimes tempted to use a plural verb with them. They are always singular, though. Each is often followed by a prepositional phrase ending in a plural word (Each of the cars), thus confusing the verb choice. Each, too, is always singular and requires a singular verb.
3. Phrases such as together with, as well as, and along with are not the same as and. The phrase introduced by as well as or along with will modify the earlier word (mayor in this case), but it does not compound the subjects (as the word and would do).
4. The pronouns neither and either are singular and require singular verbs even though they seem to be referring, in a sense, to two things.
5. The conjunction or does not conjoin (as and does): when nor or or is used the subject closer to the verb determines the number of the verb. Whether the subject comes before or after the verb doesn't matter; the proximity determines the number.
6. The words there and here are never subjects.
7. Verbs in the present tense for third-person, singular subjects (he, she, it and anything those words can stand for) have s-endings. Other verbs do not add s-endings.
8. Sometimes modifiers will get betwen a subject and its verb, but these modifiers must not confuse the agreement between the subject and its verb.
9. Sometimes nouns take weird forms and can fool us into thinking they're plural when they're really singular and vice-versa.
10. Some words end in -s and appear to be plural but are really singular and require singular verbs.
11. Fractional expressions such as half of, a part of, a percentage of, a majority of are sometimes singular and sometimes plural, depending on the meaning. (The same is true, of course, when all, any, more, most and some act as subjects.)
12. If your sentence compounds a positive and a negative subject and one is plural, the other singular, the verb should agree with the positive subject.
Subjects and verbs must AGREE with one another in number (singular or plural). Thus, if a subject is singular, its verb must also be singular; if a subject is plural, its verb must also be plural.In present tenses, nouns and verbs form plurals in opposite ways:
Patterns of singular subject-singular verb is presented in the following table :
Patterns-plural verb plural subject presented in the following table :
Although you are probably already familiar with basic subject-verb agreement, this chapter the s begins with a quick review of basic agreement rules.Subjects and verbs must AGREE with one another in number (singular or plural). Thus, if a subject is singular, its verb must also be singular; if a subject is plural, its verb must also be plural.In the present tense, nouns and verbs form plurals in opposite ways: nouns ADD an s to the singular form; verbs REMOVE from the singular form.
EXAMPLE
Singular subject-singular verb
Plural subject-plural verb
Sumber:
http://swarabhaskara.com/parts-of-speech/subject-verb-agreement-part-1/
http://grammar.ccc.commnet.edu/grammar/sv_agr.htm
http://www.towson.edu/ows/moduleSVAGR.htm
http://leo.stcloudstate.edu/grammar/subverag.html
