In three years' time, I'll be studying medicine.

[Alice Chu]

1. In three years' time, I'll be studying medicine.
1) It means that I'll be studying medicine from tomorrow to the end of three years. The duration of the repeated action, studying medicine, will be three years.
2) We can use “in three years” or “within three years” here.
Is my understanding correct?

2. In five years' time, I'll have finished studying medicine.
1) It means that I'll have finished studying medicine at the end of five years.
2) We can use “in five years” here.
Is my understanding correct?

 

[5jj]

1. In three years' time, I'll be studying medicine.
1) It means that I'll be studying medicine from tomorrow to the end of three years from now.

It doesn't. All we know is that the speaker is certain of the truth of the statement "I am studying medicine" if they utter it three years from now. We have no idea of the starting and finishing dates of the study.

 

[Skrej]

1. In three years' time, I'll be studying medicine.
1) It means that I'll be studying medicine from tomorrow to the end of three years. The duration of the repeated action, studying medicine, will be three years.

I would interpret that to mean you won't begin even begin studying medicine for another three years. The length of actual study is unknown.

Something like "In three years' time, I'll still be studying medicine" would imply that you're currently studying it and will still be doing so in three years, with the possibility of continuation beyond that third year.