这两个词在意义上非常类似。

Zhè liǎng gè cí zài yìyì shàng fēicháng lèisì.

These two words are very similar in meaning.

这个概念类似于我们学过的。

Zhège gàiniàn lèisì yú wǒmen xuéguò de.

This concept is similar to what we have studied.

他们的家庭背景相当类似。

Tāmen de jiātíng bèijǐng xiāngdāng lèisì.

Their family backgrounds are quite similar.