Thanks for helpful?

[GoodTaste]

Which is correct?

1) Thanks for helpful
2) Thanks for being helpful
3) Thanks for helpfulness
4) Thanks for the helpfulness

Thank you in advance

 

[Skrej]

Only #2 and #4 are possible, but #4 sounds unnatural.

#3 could work with the addition of a possessive adjective - i.e. 'your helpfulness'. It still wouldn't be quite as natural as #2.

 

[tedmc]

I think this is more common:

Thanks for being so helpful.

 

[Rover_KE]

I always say 'Thanks for your help'.

GoodTaste, no sentence can be correct without a final punctuation mark.