By the Time and Future Perfect tense and Future Perfect Continuous Tense

You can use “future perfect tense” (will have V3 or am/is/are going to+have+V3) with “by the time”

Examples:

(I am in London to improve my English. I will come back.)

I will have improved my English by the time I come back from England.

I am going to have improved my English by the time I come back from England.

By the time he gets home, they are going to have cleaned the entire house.


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.

Duration Before Something in the Future (Non-continuous Verbs)

With Non-continuous Verbs, we use the Future Perfect to show that something will continue up until another action in the future.(Examples are with verbs of state)

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

Future perfect tense is used with the verbs such as  “complete, finish, graduate, retire, etc ”

Examples:

(I will graduate from the university in May. I will see you in September.)

By the time I see you in September, I will have graduated from the university.

I will have finished the project by the time you arrive at the office tomorrow morning.
She will have prepared the dinner by the time we get home.
The scientists will have found the cure for cancer by 2030.

The Future Perfect Continuous tense is used with the verbs “learn, lie, live rain, sit, wait and work “which express continuous actions and show that the action will continue in the future.

Examples:

I will start working at 9 a.m. Bill will get to the office at 1 pm. (by the time..)

I will have been working for four hours by the time Bill gets to the office.

They will have been watching the film for 30 minutes by the time we arrive at the cinema.

 I was born in 1975 and it’s 2011 now. By 2040, I will have been living for 65 years.

You can use either future perfect or future perfect continuous to complete the sentence to show that continuous actions will be over in the future.

By the time my dad retires next month, he will have worked  for 40 years.

By the time he retires next March, he will have been working for our company for 30 years.