If you disagree with someone, the sentence starts: “Actually, I thought…” will sound much nicer and more polite than a terse “No” – No or “You’re wrong.”- You’re wrong. This phrase comes in handy if you have a different opinion than someone else.
A: So Tom’s coming in tonight at 8, right?
B: Actually, I thought he wasn’t working at all this week.
A: Oh, ok. I’ll have to look at the schedule again.