Be willing to do sth.

愿意做某事。

Be free to do sth. =do sth. freely

随意地或自由地做某事

Stop to do sth. (doing sth. )

停下来去做（未做的）事

Stop to do sth stop doing sth.

停下之前做的事，开始另一件。

Try to do sth and try doing sth

前者尽力，努力做某事；后者尝试做某事

Forbid sb. to do sth. forbid sb. to do sth.

也是阻止某人做某事的意思。

Stop doing sth . stop to do sth.

停下之前做的事，开始另一件。

Set out to do sth, set off doing sth

都是开始做某事

It's time to do sth. It's time for sth.

到了该去做某事的时间。

A let sb. do sth.

意为“让某人做某事”。