give (one's) twopence (worth)
To share one's opinion, idea, or point of view, regardless of whether or not others want to hear it. Primarily heard in UK, Australia. I find Jeff's husband a bit trying at times. He always has to give his twopence, even when it's clear he knows nothing about what's being discussed. If I can just give my twopence worth, I think the staff would really appreciate a bump in their pay, and productivity would increase as a result.