If you have trouble with verb tense in standard English, make a point of checking for these common trouble spots as you proofread.
Problems with verb form: writing seen for saw, for example, which confuses the past-participle and past-tense forms. (32c)
Problems with tense: using the simple past (Uncle Charlie arrived) when meaning requires the present perfect (Uncle Charlie has arrived). (32e)
Think carefully before using a regional or ethnic variety of English (she nervous) in situations calling for standard academic English (she is nervous). (See Chapter 22.)