Can I re-teach Thief to my Pokemon in Emerald?

Question

I decided to forget thief in order to learn a new move. are you ever able to get TM moves ever again?

Answer 1

Some TMs can be repurchased. However, Thief is not one of them, unfortunately. Therefore, you can never get another Thief TM in that Emerald save again, sorry.

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Hope I helped!