英语语法分析

I desire to engage in exercise and I value exercise extrinsically .

我渴望参与锻炼，我看重锻炼的外在价值。

I desire to engage in exercise and I value exercise extrinsically, not for its own sake, but as a means to something beyond it.

我喜欢锻炼并看重其外在价值，并不是因为锻炼本身，而是把它作为达到一些目的的手段。

An act doesn't have to be enjoyable when the end result is extrinsically reinforcing.

一个行动并不一定是令人愉快的，而是最终的结果得到了外在的强化。