I talk 14-6 The past perfect  should be used to describe an action already completed by the time of another past action . The simple past tense  should be used to describe a past action that took place at the same time as another past action . The perfect infinitive should be used to describe an action occuring earlier than the main action in the sentence . This sentence combines the choppy sentences by making a subordinating clause, that claims to be user-friendly. But the placement of the clause makes it seem to describe the computer, not the manual. The word Although doesn’t make sense in this context. Although means "in spite of the fact that.

I talk 27-8 The present tense is used to express a scientific truth. Weren't, the subjunctive verb form, is correct. The subjunctive mood is required in if clauses expressing a condition contrary to fact. Had left is correct. The past perfect tense is required for an action already completed at some specific past time. The present tense is used to describe fictional events in a work of literature. The perfect form of an infinitive is required for an action occurring earlier than that of the verb in the sentence. The past perfect tense (had been) should be used to describe a past event that happened before another past event (refused). The present tense (recounts) should be used to describe fictional events in a work of literature.

I talk 27-4 In formal English, the present participle form of lie, meaning "to recline," is required after the helping verbs had been. In formal English, the past-tense form of lay, meaning "to put," is required. The subject, American, is third-person singular, so the verb should be learns. A past participle, in this case supposed, is required after the helping verb have. The subject, people, is third-person plural. Only third-person singular subjects take verbs with -s endings. The subject, official, is third-person singular, so the verb should be has.  A past participle, in this case postponed, is required after the helping verb was. The subjunctive mood is required in if clauses expressing a condition contrary to fact.

I take 26-3The adverb well is correct. It modifies the verb have done. The adverb beautifully is correct. It modifies the verb thrive. When a word is longer than two syllables, using the -est ending is nonstandard. Because the verb feel is a linking verb in this sentence, the adjective bad is correct. The adverb professionally is correct. An adverb should be used to modify a verb such as could have been handled. The superlative form, easiest, should be used to compare more than two things. The word hardly is considered a negative, so the expression can't hardly is a double negative. The adverb incorrectly is correct. An adverb should be used to modify a verb such as cut.  Because of the helping verb have, the past participle sworn is required. The past-tense form swore is never used with a helping verb. The past-tense form cost is required.

I take 13-6 The pronoun is the direct object of the verb. so it should be the objective-case. the  correct pronoun becomes clear if I mentally restructure the question. which is the object of the preposition between, so the pronoun must be in the objective case. The pronoun is the object of the verb. in the subordinate clause, so it must be in the objective case The correct pronoun becomes clear if you mentally restructure the clause . The objective-case pronoun should be used as the subject of the infinitive he objective-case pronoun her should be used as the object of the verb made. You can test for the correct pronoun.

I take 12-3 The subject of the verb should be in the subjective case. The direct object of the verb suspected should be in the objective case. This becomes clear if you restructure the clause. The subject of the verb knew should be in the subjective case. The modifier of the gerund being should be in the possessive case. The object of the verb am teaching should be in the objective case. To test for the correct pronoun, try restructuring the clause. Although subjects are ordinarily in the subjective case, subjects of infinitives are an exception to the rule. The subject of to defeat should be in the objective case.

I take 25-4The subject complement of the linking verb was should be in the subjective case. The modifier of the gerund bringing should be in the possessive case. The object of the infinitive to meet should be in the objective case. The object of the preposition for should be in the objective case. The appositive renames the subject, candidates, so it should be in the subjective case. The direct object of the verb did replace should be in the objective case: whom. In questions, the direct object appears out of its normal order. To hear the correct pronoun, you can mentally restructure the question.