1. You can also experience French culture by joining many different events.

2. You can also experience French culture by taking part in joining many different events.

3. You can also experience French culture by attending many different events.
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Are they all the same in meaning? Can we substitute 'attending' for 'joining?

They all mean the same, but #2 is badly stated. You can join events or take part in them - you don't need to say both.

1. You can also experience French culture by joining many different events.

2. You can also experience French culture by taking part in many different events.

3. You can also experience French culture by attending many different events.

(Thank you. Corrected.)

MUCH better! :)

Yes, in this context, the phrases "joining," "taking part in," and "attending" can be considered synonymous and can be used interchangeably. All three sentences convey the same meaning that you can experience French culture by participating in various events. So, you can substitute "attending" for "joining" without changing the overall meaning of the sentence.