In the present perfect tense and the present perfect progressive tense, the verb 'to have' must match the singular or plural subject:
For example, in the progressive tenses, the verb 'to be' changes with the subject: When you're writing in the progressive or perfect tenses, the main verb doesn't change with singular or plural subjects - but the linking verb does.
Plural regular - The neighbors helped me.Regular past tense verbs (and most irregular past tense verbs) are the same for both singular and plural subjects. Deciding whether a verb is plural or singular mostly happens when you're writing in the present tense.
