The five basic forms of regular verbs (such as talk) follow the same pattern, adding -s, -ed, and -ing, as shown here. The forms of irregular verbs (such as speak) do not consistently follow this pattern in forming the past and the past participle (see R2-a).
Add an -s or -es ending to a verb when the subject is in the third-person singular (he, she, it, or a singular noun).
Choosing the correct verb form is sometimes complicated by English expressions. For example, used to followed by the base form of the verb does not mean the same as get used to followed by a gerund.
For more on choosing correct word forms, see W2.
Delete an -s or -es ending from a verb when the subject is in the first person (I, we), second person (you), or third-person plural (they).
Add a -d or an -ed ending to a regular verb to form the past tense or the past participle.
Check to be sure you have used the correct form of an irregular verb.
If you are uncertain about a verb form, refer to the list of irregular verbs in R2-a, or check your dictionary.
Note: Some verbs with different meanings are confusing because they have similar forms. For example, the verb lie (lie, lay, lain, lying) means “recline,” but the verb lay (lay, laid, laid, laying) means “put or place.” Consult the Glossary of Frequently Misused Words or a dictionary to make sure that you are using the correct form of the word you intend.