Which alternative contains the main clause to: "...when the fire alarm went off."?

Select the option that correctly expresses a past hypothetical situation in accordance with standard patterns of perfect modal construction in English.

Which is the best alternative to complete the statement below?
Concerning pronunciation, it's possible to affirm that sounds frequently change in connected speech. A sound may be omitted depending on the sound at the beginning of the following word or may change to resemble the neighboring word’s sound. These phonological processes are _______ and _______, respectively.

Identify the sentence in which “used to” is correctly employed.

Choose the option in which the preposition “in” is used.

The statement in which there is ellipsis of the subject is:

The relative pronoun can be omitted in:

Choose the statement in which there is an adjective that is complement to a non- finite clause.

Choose the item in which the meaning of the suffix is NOT correct.