How to use Future Perfect

Five Minute Guide to Future Perfect

Forming sentences with Future Perfect

• will have + verb 3 (past participle)

NOTE – There is no future tense in English. Instead we use a variety of forms to talk about the future. “Will” (in this case with “have + past participle”) is one of those forms. In many student grammars (and here!) this form is referred to as future perfect for convenient comparison with similar continuous/progressive forms in the present and past. See this post about tense and aspect for more.

Using Future Perfect

1. We use future perfect when an action will be complete at a specific time in the future.
   • I will have finished my project by the weekend.
   • This time next year I will have graduated college.
2. We use future perfect to predict the present.
   • Don’t bother going to see him, he’ll have left.
   • It’s 6 o’clock, hurry up! The film will have started.

Future Perfect in detail

How do we form Future Perfect?

To form future perfect we use the modal verb will, the auxiliary verb have in its base form and the past participle form of the main verb, like this:

• will + have + past participle

Here are some examples:

• They will have left.
• We will have been here for two days.

Future Continuous questions

We make “yes/no” and object/adverb questions by inverting the subject and auxiliary verb. With future perfect, however, we have two auxiliary verbs, will and have, so we just invert the first one, “will”, with the subject. The other one, “have”, stays with the main verb:

• Will they have left? (yes/no question)
• Why will they have left? (object or adverb question)
• Who will have left? (subject question)

Future Perfect negatives

To make a negative future perfect sentence, we use one of the auxiliary verbs (will) and “not”. The second auxiliary verb, “have”, stays with the main verb. Here are some examples:

• They will not have left.
• We won’t have been here for two days.

When do we use Future Perfect?

1. Events that will be complete at a specific time in the future

   Have a look at this sentence:

   • The team will have finished the project by Friday.

   What can we say about when the project will be complete in this example? Well, what we’re doing here is imagining a specific time in the future (Friday) and saying that at some point between now and that specific time, the project will be complete.

   We often use the word “by” to introduce the specific time in the future that we’re thinking about. “By” in this sense means “on or before” – in other words, “Friday at the latest”.

   Here’s another example:

   • This time next week I will have graduated college.

   Once again we are saying that if we project ourselves forward in time to “this time next week” the action of graduating college will be complete. It will be completed at some point between now and that specific point in the future. The word “by” in this example is implied – we could have said “by this time next week…”.

   Now, let’s compare this with some other forms of the future:

   • This time next week I will have graduated college. (future perfect)
   • This time next week I will be graduating college. (future continuous)
   • This time next week I will graduate college. (will)

   Can you see the differences in meaning when we compare future perfect with “will” and future continuous?

   • With the first sentence (future perfect), we mean “on or before this day next week”.
   • The second sentence (future continuous) means that the action of graduating college will be in progress on this day next week.
   • The last one (will) is a prediction or assumption about what will happen on this day in a week’s time.

2. Predictions about the present

   Just as we can use future continuous to make predictions about the present, we can use future perfect to do the same thing. Have a look at this sentence:

   • Don’t bother going to see John, he’ll have left already.

   Here I’m predicting that John left at some undefined time between the past and now.

   Let’s compare this with present perfect. One use of present perfect is to talk about events that happened at an unspecified time in the past, up to the present. So, if we were 100% sure that John had left, we would say this:

   • Don’t bother going to see John, he has left already. (present perfect)

   Using future perfect gives us exactly the same meaning, except that we are not sure – we are predicting rather than stating a fact.

Future Perfect Continuous

Just as we have present perfect continuous and past perfect continuous, we can make a similar form to talk about the future. We form it like this:

• will + have been + present participle

We use this form to emphasise the fact that an action is longer in duration and will continue up to the point in the future that I’m talking about.

Here’s an example:

• On Friday I’ll have been working in this job for 10 years.

Just like before I’m imagining a specific time in the future (Friday). This time though, rather than focusing on the fact that an action will be complete on or before that time, I’m focusing on the action of working and the duration of this action up to that point in the future.

Related grammar points

Future Continuous
Will and Going to
Tense and aspect