Auxiliary Verbs Exercises PDFSet 3: Mixed Auxiliary Verbs: Advanced Practice

1."has"(c)

The original sentence uses the present perfect ('haven't finished'). In ellipsis, we replace the repeated verb phrase with just the auxiliary, matching the new subject. 'Sarah' is third person singular → 'has' (= has finished). Not 'does' (wrong auxiliary — the tense is present perfect, not present simple), not 'haven't' (wrong person and wrong polarity — Sarah HAS finished), not 'is' (wrong auxiliary).

2."can"(a)

After 'neither', we use the POSITIVE form of the same auxiliary because 'neither' already carries the negative meaning. The original uses 'can't', so we need 'can': 'Neither can his brother' = his brother also can't drive. Not 'can't' (double negative — 'neither can't' is incorrect), not 'does' (wrong auxiliary), not 'could' (wrong tense).

3."do"(b)

'Love' is a main verb in the present simple. When expressing agreement with 'so', we use the auxiliary that matches the tense and subject. Present simple + first person 'I' → 'do'. 'So do I!' means 'I also love pizza.' Not 'does' (wrong person — 'does' is for third person), not 'am' (wrong auxiliary for present simple), not 'love' (we use an auxiliary in this structure, not the main verb).

4."will"(d)

Like 'neither', 'nor' already carries negative meaning, so we use the POSITIVE form of the auxiliary. The original uses 'won't' (= will not), so we need 'will': 'Nor will her sister' = her sister also won't come. Not 'won't' (double negative — 'nor won't' is incorrect), not 'does' (wrong auxiliary — the original uses 'will'), not 'can' (wrong modal).

5."will have"(c)

'By next week' refers to a point in the future, and 'completed' is a past participle. This is the future perfect tense: 'will have' + past participle. It expresses an action that will be finished before a future deadline. Not 'have' (present perfect — no future reference), not 'will' (future simple — 'will completed' is ungrammatical), not 'would have' (conditional, not a definite future plan).