the thing is|thing is

我很想来，但问题是，我有其他安排。

I'd love to come, but ___the ___thing ___is, I have other plans.

关键是我已经看过那部电影了。

___The ___thing ___is that I've already seen that film.

有趣的是，我们上的是同一所学校。

The funny ___thing ___is that we went to the same school.