No one likes to hear complaints; they give most people a downer feeling.

Instead of complaining, request. Requests establish a positive tone and invite helpful responses and solutions.
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Complaint: “I hate …”
Complaint: “Why do we always …”
Complaint: “I don’t like that ….”
Complaint: “It bugs me when …”
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Request: “How about …?”
Request: “How would you feel …?”
Request: “What are your thoughts about …?”
Request: “What do you think about ….?”