Sheila had an ulterior motive for trying to help Stan.

希拉设法帮助斯坦是别有用心。

She must have some ulterior motive for being nice to me—what does she really want?

她对我这么好，一定别有用心—她到底想干什么呢？

I have an ulterior motive in offering to help you.

我主动提出要帮助你是有私心的。

Their groundless accusation is made with ulterior motives.

他们的无端攻击是别有用心的。

He has ulterior motives.

他别有用心。