Future Perfect Tense

I will have sung

The future perfect tense is quite an easy tense to understand and use. The future perfect tense talks about the past in the future.

How do we make the Future Perfect Tense?
The structure of the future perfect tense is:

subject --- + --- auxiliary verb WILL --- + --- auxiliary verb HAVE --- + --- main verb
-------------------------invariable ----------------------invariable -----------------past participle
----------------------------will --------------------------------have -------------------------V3

Look at these example sentences in the future perfect tense:

----subject --------auxiliary verb -----------------auxiliary verb ------------main verb------------
+ ---I ----------------will -------------------------------have -----------------------finished --------by 10am.
+ ---You ------------will -------------------------------have -----------------------forgotten ------me by then.
- ---She ------------will ------------------not --------have ------------------------gone -----------to school.
- ---We -------------will ------------------not --------have ------------------------left.
? ---Will ------------you --------------------------------have -----------------------arrived?
? ---Will ------------they -------------------------------have -----------------------received -------it?

In speaking with the future perfect tense, we often contract the subject and will. Sometimes, we contract the subject, will and have all together:

I will have -------------------------I'll have ------------------------------I'll've
you will have -----------------.---.you'll have --------------------------you'll've
he will have -----------------------he'll have ----------------------------he'll've
she will have ----------------------she'll have ---------------------------she'll've
it will have -------------------------it'll have -----------------------------it'll've
we will have -----------------------we'll have ---------------------------we'll've
they will have ---------------------they'll have -------------------------they'll've

We sometimes use shall instead of will, especially for I and we.


How do we use the Future Perfect Tense?
The future perfect tense expresses action in the future before another action in the future. This is the past in the future. For example:

•The train will leave the station at 9am. You will arrive at the station at 9.15am. When you arrive, the train will have left.

The train will have left when you arrive.

past -------------------------------------------present ----------------------------------------future
------------------------------------------------------------------------------------Train leaves in future at 9am.
------------------------------------------------------------------------------------------------------------------9 9.15

------------------------------------------------------------------------------------You arrive in future at 9.15am.
-----------------------------------------------------
---------------------------
Look at some more examples:

•You can call me at work at 8am. I will have arrived at the office by 8.
•They will be tired when they arrive. They will not have slept for a long time.
•"Mary won't be at home when you arrive."
"Really? Where will she have gone?"

You can sometimes think of the future perfect tense like the present perfect tense, but instead of your viewpoint being in the present, it is in the future:

present perfect tense -------------------------------- future perfect tense

have
done
----->
-------------------------------------------.---........--------------------- will
---------------------------------------------------.......----------------- have
-----------------------------------------------.-------.......--------------done
-----------------------------------------------------------......-------------->

----------------------------------------------------------------------------------------

past ----- now ----- future -------------------- past ----- now ----- future