他跟我们在一起时总是很拘谨。

He was always very ___stiff with us.

他拘谨的态度使得很难进行随意的交谈。

His ___stiff attitude made it hard to have a casual conversation.

她在正式晚宴上拘谨的举止暴露了她的紧张。

Her ___stiff manner at the formal dinner betrayed her nervousness.