Future Perfect Verb Tense

“She will have gone to the store by the time we get home.”

The future perfect is a verb construction that tells about something that will take place in the future that is related to another event of some sort that will also take place in the future. These events are not dependent on each other but are used to indicate time relationships.

The future perfect tense describes an expected, predicted, or planned event that will take place at a point in the future, and in reference to another event that will take place before the original event happens. 

This utilizes the verbs “will” and “shall.” It uses the future tense combined with a perfect tense.

Remember, a perfect tense is an event that is complete already. So to use the two together, you use a future word (will, shall) and juxtapose it with an event that has already been completed or will have been completed by the time that the future event is supposed to take place.

This can seem complicated. It’s actually not and you probably already use this form regularly all the time and just don’t necessarily think about it! For example, say you are discussing with a friend about a time that she should come over. You suggest that she comes over at 7pm on Saturday. She disagrees saying: 

“No, I won’t be able to come then because, by 7 pm, I will have left for my mom’s house for the weekend.” 

Your friend is using the negative form of future perfect to describe a juxtaposed event in the future that makes it impossible for her to come at the time you suggested. 

When To Use the Future Perfect Tense

Sometimes, you use the future tense and simple future interchangeably. The difference is that future perfect doesn’t need prepositions in it to make it make sense. 

For example, “I thought she would be here before ten pm if there were no problems with traffic?” 

Vs. 

“She should have been here by ten pm since there was no traffic. “

So future tense relies on the word “before” to clarify its meaning, while future perfect has an event that has already happened to do that job. 

When Not to Use the Future Perfect Tense

The future perfect tense is for actions that will be completed at a certain point in time due to something that is identifiable. It does not apply if there is no “deadline.” If there is no specified endpoint, then it is not necessary to use the future perfect tense. 

She will leave to go to the coast. (No specified deadline)

Vs. 

She will have left for the coast by 7 pm this evening. (A specified deadline). 

Form the Future Perfect Tense

Forming the future perfect tense is easy: will have + (past participle). It doesn’t matter if the subject of your sentence is singular or plural. The past participle with the “will have” is a good indicator of the future perfect tense. 

Statement	Question	Negative
I will have boarded the flight by ten pm tomorrow.	Will I have boarded the flight by ten pm tomorrow?	I will not have boarded the flight by ten pm tomorrow.
You will have gone to the store by 8 pm tomorrow.	Will you have gone to the store by 8 pm tomorrow?	You will not have gone to the store by 8 pm tomorrow.
She will have left the west coast by the time you get up tomorrow.	Will she have left the west coast by the time you get up tomorrow?	She will not have left the west coast by the time you get up tomorrow.
He will have wanted to be done with his assignments by Thanksgiving.	Will he have wanted to be done with his assignments by Thanksgiving?	He will not have wanted to be done with his assignments by Thanksgiving
They will have gone to the store by 8 pm on Wednesday.	Will they have gone to the store by 8 pm on Wednesday?	They will not have gone to the store by 8 pm on Wednesday.
We will have gone to the bus station by this time tomorrow.	Will we have gone to the bus station by this time tomorrow.?	We will not have gone to the bus station by this time tomorrow.
It will have been two years before we will have gone back to China.	Will it have been two years before we will have gone back to China?	It will not have been two years before we will have gone back to China.

When to Use the Future Perfect Tense

To Say ‘How Long’

To say ‘how long’ for an action that starts at a given time before another event and continues until a time in the future. It describes how long you have known or been doing a specified action or event. This is to offer an extra definition and extra time specified. 

“When we go to the coast it will have been four years since the last time I went.”

“At 10 pm I will have been awake for 18 hours.”

Examples include:

Example:	Explanation:
At 8 pm I will have been running for four hours.	The narrator has been running for several hours.
We will have been going to this movie theater for three years this May.	Going to the movie theater is a routine.
He will have been at this school for four years this year.	Four years is a long time at the school.
The bus will have left by the time we get to the station.	The bus schedule indicates that we will be late.
The bus will have left by 10 pm when we get there.	The bus will be gone by the time we arrive.

To Indicate a Future Time Or to Talk About An Action That Will Finish

We use the future perfect and a “future time word” (this word is very often the word “by”) to indicate an action that will have started at a particular time but that we do not know when it will end exactly.

“I will be back at the house by 10 o’clock.” (I will be back before 10 but I am uncertain exactly when.) 

“By the time I’m sixty-five, I will have retired from teaching.” (I will have retired by sixty-five, but I am not certain of the year, maybe sixty, maybe fifty-nine, or maybe fifty-two if I win the lottery.)

Example:	Explanation:
By eight pm I will be home.	I will be home by 8, but maybe a little before that.
By 2021 we will have lived here for six years.	Unspecified time in 2021, we will have lived there for six years.
By tomorrow he will have been gone for two weeks.	He will have been gone two weeks at an unspecified time tomorrow.
By the time it gets here, the bus has been late for quite a while.	The bus is late already and continues to get later.
The bus will have been gone for an hour by the time we get there.	The bus will be gone for some time when we get there; it is implied there is no reason to go now.

To Indicate a Future “If” Contingency

We use the future perfect to indicate a future time contingency. “If —— then——- I will have been———“ This future time contingency is dependent on the “if’ part of the sentence and indicates possibility. 

Example:	Explanation:
If I get home by eight then I will have been able to get home in time for dinner.	If I get home by 8 I will get dinner.
If we go to the mall tomorrow we will have been searching for this shirt for two weeks.	I have been trying to find a particular item in many places for two weeks. If I go to the mall tomorrow, it will be two weeks of searching.
If he doesn’t find a job he will have been looking for three months.	Soon it will be three months that he has been looking for a job.
If the bus is late tonight this will have been the fourth consecutive time I have been waiting.	This is getting to be a pattern.

A Note On Future Perfect Tense

Future perfect is a useful tense for showing the construction that tells about something that will take place in the future and is related to another event that will occur at another point in the future. The two events may or may not be contingent on each other. They may simply be time-stamped situations that are unrelated or they may be dependent. Often the use of the word “if” indicates a dependence, but not always. 

The future perfect tense describes an expected event that is followed by another event that will indicate the completion or finish of the first event.