Do you know when you are going to struggle getting a word out?

Do you know when you are going to struggle getting a word out? When I am trying to have a conversation I already know that I'm not going to be able to say a word so I am constantly changing what I'm about to say to get to the same point, I'm not talking about a list of words that I already have trouble with. When a conversation is free flowing I am editing it in real time if that makes any sense, for example, if someone asks me where I went last night, I might not be able to get that word out so I will start describing where it is until I can say the name of the place or I might have said enough to get my point across and avoid that word altogether. Basically I can already tell before I try to say the word