What does “bien” mean in “je pense bien que”?

After a verb of opinion, bien stops meaning “well” and becomes a booster. Je pense bien que… is “I really do think,” not “I think well.” The same move gives je crois bien (“I rather think”), j’espère bien (“I certainly hope so”) and j’ai bien envie (“I’ve a real mind to”). It belongs to speech, and it is one of the fastest ways to stop sounding like a textbook.

Position matters: bien sits immediately after the conjugated verb — je pense bien que…, j’ai bien entendu (“I heard you loud and clear”). Two cousins are worth separating out: je veux bien is not “I want well” but “sure, happy to,” and bien sûr is simply “of course.” This nervous auditionee uses two of the patterns within seconds — je pense bien que je suis un petit peu trop nerveux and on a bien entendu.