An auxiliary expressing conjecture or appearance ("it seems that..."). Used after the attributive form of verbs/adjectives and as のようだ after nouns.
外が暗いから、雨が降るようだ。
It's dark outside; it seems it will rain.
彼は昨日から来ていないから、病気のようだ。
He hasn't come since yesterday, so he seems to be ill.
話し方からすると、彼は先生のようだ。
Judging by the way he speaks, he seems to be a teacher.
鍵が見つからない。なくしたようだ。
I can't find the key. It seems I lost it.
An auxiliary expressing likeness or similarity ("is like...").
この布は絹のようだが、触ると少し違う。
This cloth is like silk, but it feels a bit different.
彼の考え方は子供のようだ。
His way of thinking is like a child's.
その音は鐘のようだと感じた。
I felt that the sound was like a bell.