Finishing others sentences

Whenyou are asked to do it there is no issue. If you do it on your owm then you are a 'know it all'

No, I don't usually finish others sentences for them. It drives me nuts when somebody does that to me, and I won't do it to somebody else. The only thing I do that comes close to it is when somebody is searching for the word for something and outright asks or says they can't remember the word for __________.

I do it all the time (I do try to stop myself!) but then I probably am a "know it all".