Question

1. Are you planning to go to Australia for your vacation?
2. Are you planning to go to Australia on your vacation?
3. Are you planning to go to Australia for the purpose of your vacation?
4. Are you planning to go to Australia at the time of your
vacation?

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Does #1 mean #2 or #3? Does #1 mean #4? Is there any difference between #1 and #2?

Answer 1

They all mean approximately the same thing, but 3 and 4 are very wordy!

1 and 2 are fine and are used a lot.