to tell the truth... 老实说……
该句用来表达自己的真实想法。同类的表达形式很多，如："truth to tell...；frankly speaking...；to be honest..."。
1. To tell the truth, I forgot it was your birthday last week.
2. Frankly speaking, I don't like Beijing Opera.
3. To be honest, that red blouse does not match your skin.
A: May I have a look at that vase, please?
B: Of course. It's the best one I have here - and it's only 300 yuan.
A: Oh, it's really nice, but to tell the truth, that's far too expensive.
B: Really? Even for such an excellent one?