1. Mind the bag in my absence.

Question

2. Mind the bag while I am away.
3. Mind the bag when I am away.
4. You should mind the bag in my absence.
5. Did you mind the bag in my absence?
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Can we use all the expressions? Are they all grammatical?

Can we use 'watch' instead of 'mind' here?

Answer 1

They are all fine. In the U.S. we would be more likely to say "watch the bag"; in the U.K, "mind the bag". They both mean the same thing. Both mean, "Pay attention and don't let anyone steal the bag."