Grammar

Future Perfect Continuous tense

1,960 fill-in-the-gap exercises across 4 forms

For how long an activity will have lasted by a future point. The rarest English tense, and the most predictable once you see the shape.

Pick a form to practice

When you need it

One job, and it needs two things to work: a future deadline and a length of time.

By the end of the month, they will have been building the bridge for two years.

Take either away and the sentence collapses into a different tense.

The shape

Four fixed pieces, identical for every subject: will have been plus the -ing form. Nothing agrees, nothing changes.

I will have been waiting. She will have been waiting. They will have been waiting.

Once you can see the pattern, this is the most mechanical tense in English.

Perfect or perfect continuous

The familiar split, moved into the future:

• By Friday she will have written three reports. — how many, the result.
• By Friday she will have been writing for a week. — how long, the activity.

If the sentence contains a number of finished things, use the plain form. If it contains for plus a stretch of time, use this one.

Which verbs will not fit

Two groups:

• State verbs — know, understand, believe, want, own, belong. By then we will have known each other for a decade.
• Verbs that describe a single completed moment — finish, arrive, leave, start, break. You cannot be in the middle of arriving, so will have been arriving is wrong.

Explaining a future state

Like the other perfect continuous tenses, it often supplies a cause:

She’ll be exhausted when she lands — she will have been flying for fourteen hours.

All forms

Mistakes to avoid