Auxiliaries

Auxiliaries explanation:

https://www.ego4u.com/en/cram-up/grammar/auxiliary-verbs

Exercises (do them in this order please):

https://www.ego4u.com/en/cram-up/grammar/auxiliary-verbs/exercises

https://www.ego4u.com/en/cram-up/grammar/auxiliary-verbs/exercises?ex02

https://www.ego4u.com/en/cram-up/grammar/auxiliary-verbs/exercises?ex03

https://www.ego4u.com/en/cram-up/grammar/auxiliary-verbs/exercises?ex04

https://www.ego4u.com/en/cram-up/grammar/auxiliary-verbs/exercises?ex05

https://www.ego4u.com/en/cram-up/grammar/auxiliary-verbs/exercises?ex06

https://www.ego4u.com/en/cram-up/grammar/auxiliary-verbs/exercises?ex07

https://www.ego4u.com/en/cram-up/grammar/auxiliary-verbs/exercises?ex08

https://www.ego4u.com/en/cram-up/grammar/auxiliary-verbs/exercises?ex09

https://www.ego4u.com/en/cram-up/grammar/auxiliary-verbs/exercises?ex10