I can not login to mac book pro When i turn on my MacBook and select user and then enter password , it does not accept my password, after 3 or 4 times entering password it works, i do know how to solve this problem.
This is a very strange issue. However check for the default keyboard, and also try changing your password to just numbers. That way you can confirm if its something to do with the keyboard language.

However, its better to create a new user account and confirm. If you have the issue take it to an AppleStore or just try to reinstall the OS on top. That way it will fix if there are any issues due to a malware.