We're not a hundred per cent certain, right?

我们不是百分之百确定，对吧？

They're comfortable in the language even if it's not a hundred per cent perfect.

他们对这门语言感到非常舒适，即使并不是百分之百的完美。

If you're not a hundred per cent sure whether the other person is ready to say " I love you" back to you then definitely go for this one.

如果你没有百分之百的把握另一个人准备好对你说“我爱你”的话，那就说这个吧。