他似乎没有发现我的存在。

Tā sìhū méiyǒu fāxiàn wǒde cúnzài.

He didn't seem to notice my existence.

我们的前景似乎不太乐观。

Wǒmen de qiánjǐng sìhū bú tài lèguān.

Our prospects seem to be not that optimistic.

他似乎对这个问题不太了解。

Tā sìhū duì zhège wèntí bù tài liǎojiě.

He seems to be unfamiliar with this issue.