Question

to tell you the truth是什么意思

Answer 1

to tell you the truth
实话告诉你
双语对照
例句:
1.
To tell you the truth, the guy was a creep.
实话告诉你,这家伙是个卑鄙小人。

2.
To tell you the truth, I'm as shocked as you are.
跟你讲实话，我跟你一样吃惊。

Answer 2

英语口语的插入语,没法也无需分析成分.
能用作插入语的不定式短语有：to be frank,to be honest,to be sure,to tell you the truth,to make matters worse,to sum up,to start with,to begin with等.
例句：　
To be frank,I don’t quite agree with you.　坦率地说,我不太同意你的意见.
To tell you the truth,I’m not so interested in the matter.　跟你说实话,我对这件事情的兴趣不大.
To sum up,success results from hard work.　总而言之,成功是艰苦努力的结果.