Future Perfect Tense: How to use?

Future Perfect has two different forms: “will have done” and “be going to have done.” Unlike Simple Future forms, Future Perfect forms are usually interchangeable.

FORM Future Perfect with “Will”

[will have + past participle]

Examples:

You will have perfected your English by the time you come back from the U.S.
Will you have perfected your English by the time you come back from the U.S.?
You will not have perfected your English by the time you come back from the U.S.

FORM Future Perfect with “Be Going To”

[am/is/are + going to have + past participle]

Examples:

You are going to have perfected your English by the time you come back from the U.S.
Are you going to have perfected your English by the time you come back from the U.S.?
You are not going to have perfected your English by the time you come back from the U.S.

NOTE: It is possible to use either “will” or “be going to” to create the Future Perfect with little or no difference in meaning.

The Future Perfect expresses the idea that something will occur before another action in the future. It can also show that something will happen before a specific time in the future.

Examples:

By next November, I will have received my promotion.
By the time he gets home, she is going to have cleaned the entire house.
I am not going to have finished this test by 3 o’clock.
Will she have learned enough Chinese to communicate before she moves to Beijing?
Sam is probably going to have completed the proposal by the time he leaves this afternoon.
By the time I finish this course, I will have taken ten tests.
How many countries are you going to have visited by the time you turn 50?

Notice in the examples above that the reference points (marked in italics) are in Simple Present rather than Simple Future. This is because the interruptions are in time clauses, and you cannot use future tenses in time clauses.

USE 2 Duration Before Something in the Future (Non-Continuous Verbs)

With Non-Continuous Verbs and some non-continuous uses of Mixed Verbs, we use the Future Perfect to show that something will continue up until another action in the future.

Examples:

I will have been in London for six months by the time I leave.
By Monday, Susan is going to have had my book for a week.

Although the above use of Future Perfect is normally limited to Non-Continuous Verbs and non-continuous uses of Mixed Verbs, the words “live,” “work,” “teach,” and “study” are sometimes used in this way even though they are NOT Non-Continuous Verbs.

Subject + WILL HAVE + Verb (past participle form)

Quick examples

I will have graduated from university by May.
Patrick will have lived in Hong Kong for 20 years by the next month.
The train will have left by now.

We use the Future Perfect tense to talk about actions that will be finished before some point in the future. We also use this tense to express situations that will last for a specified period of time at a definite moment in the future. The last use is to express certainty that an action was completed.

Use

Use 1: Completion before a specified point in the future

The first use of this tense is to talk about future actions that will be finished before some specified point in the future.

Before they come, we will have cleaned up the house.
John will have eaten the whole cake, by the time the birthday party starts!

Use 2: Duration in the Future

Another use of this tense is to talk about actions will last after a given point in the future.

By the next year, I will have known Monica for 30 years.
Patrick will have lived in Hong Kong for 20 years by 2012.

Common Time Expressions

Time expressions that are commonly used with the Future Perfect:

By
By the time
Before
By tomorrow/7 o’clock/next month
Until/till

Use 3: Certainty About the Near Past

The last use is to express conviction that something happened in the near past.

The train will have left by now. We have to look for another way to get there. (I’m sure the train has left)
The guests will have arrived at the hotel by now. (I’m sure the guests have arrived at the hotel)

Form

WILL = ‘LLExample: She’ll have finished = she will have finished WILL + NOT = WON’T Example: She won’t have finished = she will not have finished

Important

The Future Perfect appears in two forms: “will” form and “going to” form which can be used interchangably. Example:

“She will have finished” means “she is going to have finished”

Positive Sentences

Subject	+	Auxiliary verb	+	Auxiliary verb	+	Past participle
e.g. I/a dog etc.	+	will	+	have	+	e.g. eaten/given/gone etc.

Examples		Use
	I will have retired by the end of this year.	(Use 1)
	I read 40 pages a day. If I keep up the pace, I will have read the book by Tuesday.	(Use 1)

Questions

Auxiliary verb	+	Subject	+	Auxiliary verb	+	Past participle
will	+	e.g. I/a dog etc.	+	have	+	e.g. eaten/given/gone etc.

Examples		Use
	Will they have graduated from Cambridge by July 2009?	(Use 1)
	Will I have retired by the end of the year?	(Use 1)
	Will you have bought a new processor by the end of this week?	(Use 1)

Negative Sentences

Subject	+	Auxiliary verb + not	+	Auxiliary verb	+	Past participle
e.g. I/a dog etc.	+	will not	+	have	+	e.g. eaten/given/gone etc.

Examples		Use
	They won’t have graduated from from Cambridge by July 2009.	(Use 1)
	My uncle won’t have retired by the end of the year.	(Use 1)

REMEMBER No Future in Time Clauses

Like all future forms, the Future Perfect cannot be used in clauses beginning with time expressions such as: when, while, before, after, by the time, as soon as, if, unless, etc. Instead of Future Perfect, Present Perfect is used.

Examples:

I am going to see a movie when I will have finished my homework. Not Correct
I am going to see a movie when I have finished my homework. Correct

ADVERB PLACEMENT

The examples below show the placement for grammar adverbs such as: always, only, never, ever, still, just, etc.

Examples:

You will only have learned a few words.
Will you only have learned a few words?

You are only going to have learned a few words.
Are you only going to have learned a few words?

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