How do you respond when someone with dementia struggles to come up with a word?

There are times where my boss or my Dad can't seem to pull the word out that they are looking for [neither one has dementia, just normal age decline]... they have no problem with me saying the word if I use the word like a question.... "you mean Perry Como?"

It's really hard to resist the urge to fill in the blanks. With my Dad, if it's obvious what the word is I'll chime in and he'll keep rambling. But I've learned to avoid "Twenty Questions".

When he gets stuck and I don't have a clue where he is trying to go I usually very gently change the subject to a sure thing, like the weather. " Sure is hot today". And away we go on someting he can deal with, forgetting about the word or name he forgot earlier.