1. open：公开的，坦率的

Don’t hid secret of oneself, and willing to express oneself and expose the weakness.

例：

Lucy is open to her good friend, and never hid her true feelings.

露西对好朋友很坦率，从不隐藏她的真实情感。

He is not open enough to his parents.

对他的父母，他没那么的坦率。

2. frank：坦白的，坦率的

Emphasizing speak freely and unreservedly, without any constraint.

例：

To be frank, I don’t like your friend Tom.

坦白的说，我不喜欢你的那个叫汤姆的朋友。

It is obvious that your client is not that frank with you.

很明显你的委托人对你不够坦率。

Frankly speaking, you love me not more than I love you.

坦白地说，你并没有我爱你那样地爱我。

3. sincere：真诚的，诚挚的

It focuses on that someone express a kind of inner sincerity for somebody or something.

例：

He begged your pardon with sincere desire.

他真心诚意地祈求你的原谅。

He is sincere in his words.

他的话很真挚。

We all long for sincere and eternal friendship.

我们都渴望真诚永恒的友谊。

4. honest：诚实的，坦率的

It refers to abide by the moral principles, such as integrity.

例：

I hope you are honest about what you did.

我希望你能对你的所作所为没有一丝隐瞒。

People who are honest despise lies.

诚实的人蔑视谎言。

He is a really honest man.

他真的是一个诚实的人。

5. plain：坦率的，爽快的

It points that someone speaks his mind with no affectation and false.

例：

Could you be much plainer?

你就不能爽快点儿？

If you are plain to me, I will do so to you.

如果你对我坦率，我对你也会毫无隐瞒。

英语外教一对一课程免费体验：http://www.acadsoc.com.cn/lps/common/lp-tutor.htm?search=350982