Could I also say "I would like to postpone Tuesday lessons until Thursday or Friday". ?
Cheers
W
Yes.
If you are the teacher, you could say, "I'd like to move next Tuesday's lesson to Thursday or Friday."
If it's a permanent arrangement, "I'd like to move the Tuesday lesson to Thursdays or Fridays."
If you're a student and it's a private lesson, you could say, "I'd like to postpone next Tuesday's lesson until Thursday or Friday." or "I'd like to change the day for my lesson from Tuesdays to Thursdays or Fridays."
There's really a lot of ways of saying this, depending on the circumstances. In any case, you should be as specific as possible about what you mean, especially if it's in writing.