As a verb:
* My coworker constantly gripes about the new coffee machine. (Complaining)
* The kids griped about having to clean their rooms. (Whining)
* I'm not going to gripe about the weather, it's just how it is. (Expressing a minor complaint)
As a noun:
* My biggest gripe with the new phone is the battery life. (Complaint)
* He had a whole list of gripes about the company's policies. (Complaints)
* Don't let your gripes about work affect your home life. (Problems)
Informal:
* "Ugh, I have such a gripe about this new software," she said. (Strong dislike)
* We had a gripe session about the latest episode of the show. (Informal discussion of complaints)
It's important to note that "gripe" often has a negative connotation, implying complaining or whining.