We generally use by/in with the future continuous and by/in with the future perfect.

I'm only halfway through my homework. I __________ (not finish) it before the teacher arrives.

Our table at the restaurant is at 1 p.m. Do you think we'll have ________ lunch by 3 p.m.?

Don't phone me before 8 o'clock, we ___________ (have) dinner.

Next week we'll ________ been together for two years.

When you get off the train, we _______ for you on the platform. [ 'll be waiting ] [ 'll have waited ]

I'm taking the day off on Friday – I ______ be working.

Julie _____________ (not work) this time next week. She'll be on holiday!

When you get off the train, we _______ for you on the platform. [ 'll be waiting ] [ 'll have waited ]

We'll have _____________ a bit of Korean by the time you come to Seoul.

In less than 2 years, my grandparents _______ for 50 years. We are going to celebrate it. [ will have been married ] [ will be getting married ]

In their retirement, they'll _______ living in a small house in the mountains.

By June next year, I _______ have retired from work.