Hello, can ı use a paper wallet twice ?
Yes you can, but whether you
should depends.
As long as you are only
receiving coins, there's little wrong with reusing your paper wallet (except for potential privacy concerns as pointed out by Velkro).
Once you import the private key of your paper wallet to
spend coins, there's 2 things to be aware of:
1) Depending on what wallet and which configuration you use, the remainder of your balance might get sent to a change address (as mentioned by biggNY)
2) Once you import your private key to an online device (such as an internet connected laptop or smartphone), you lose all benefits of cold storage (ie. your cold storage paper wallet is now only as secure as a regular hot wallet).
For security reasons I personally wouldn't reuse a paper wallet after I have swiped the private key, but that depends on your personal preference and the amount at risk I guess.