never would have guessed
1. never would have thought something to be the case. (Not used in other tenses.) He was the one who did it? I never would have guessed. I never would have guessed that he wanted the job. He kept it a very good secret.
2. knew it all the time because it was so obvious. (Sarcastic. Not used in other tenses.) I never would have guessed that he wanted the job. He only begged and begged for it. Now she wants to go back home? I never would have guessed! She has been homesick for days.