Expressing "It looks like..."

In Japanese, the word そう can be used with adjectives to express that something is seemingly [adjective]. For example, if I say "That apple looks good!" I don't know if it's good yet, but I'm stating what I think to be true based on my visual impression.

To do this in Japanese, the following rules are used:

I-Adjectives:

• Drop the い and add そう
• 新しい -> 新しそう

Na-Adjectives:

• Simply add そう
• 簡単 -> 簡単そう

Exception:

•  いい becomes よさ
• Then そう is added
• いい -> よさそう

その車は新しそうだね。
That car looks new.

田中先生のテストは簡単そうですよ。
Tanaka-sensei's test looks easy.

今夜交通はよさそうですね。
Traffic this evening looks fine.

The same can be done with negative adjectives. This time, the ない in the negative ending is replaced with なさ, then そう is added.

山登りは難しくなさそうね。
Mountain climbing doesn't look difficult.

ジムの息子と遊ぶことは楽しくなさそうだよね。
Playing with Jim's son does not look fun.

Of course, putting the negative on the そう (instead of the adjective itself) is also fine, though I'll have to see if there's any difference in nuance here.

その図書館は静かそうじゃないね。
That library does not look quiet.

最近リーさんは元気そうじゃない。
Lee-san doesn't look well lately.

Adjectives that use そう can also be used to qualify other nouns, just like a standard na-adjective.

にぎやかそうな都会に行った。
We went to a lively-looking city.

それはきつそうなドレスだね。
That is a tight-looking dress.

Finally, そう can also be used with verbs to have a similar "looks like" effect. そう is simply added to the verb stem.

カナトは泳げそうだね！
It looks like Kanato can swim!

アリスは友達の家に行きそう。
It looks like Alice is going to her friend's house.

It's important to note that while this usage of そう is often based on visual clues, it is not limited to that sense alone. It would be strange to say something like きれいそう about a painting in front of you, because if something is pretty, you're already aware of that fact due to its visual medium. As Genki says, "if it looks pretty, then we already have enough evidence to conclude that it is pretty."