と's role in 「それは触ると柔らかい」

Question

I found out this sentence:

それは触{さわ}ると柔{やわ}らかい

and I don't understand と sentence in here. I know と is related to "and" and "with". But what's its role on this sentence?

Answer 1

と has quite a few meanings. To name a few...

The case particle (格助詞) と can mean "and" or "with". It attaches to 体言, such as nouns and pronouns. eg:

• 「りんごとみかん」(apples and oranges)
• 「わたしと一緒に」(together with me)

The case particle と can also be used as a quotative particle. It attaches to almost anything, eg:

• 「おいしいと思う」(I think it's tasty)
• 「買うと言った」(I said I would buy it)
• 「今日の晩ご飯はトンカツ(だ)と聞いた」(I heard today's dinner is tonkatsu)

The と in your example is a conjunctive particle (接続助詞) meaning "When~" or "If~". It attaches to 用言, such as verbs, adjectives, auxiliaries. eg:

• 「食べると太る。」(If you eat, you'll gain weight.)
• 「暗いと見えない。」(If/When it's dark, I can't see.)

So your sentence それは触ると柔らかい means "It feels soft when/if you touch it."

Answer 2

According to "A Dictionary of Basic Japanese Grammar", page 480:

と: a subordinate conjunction which marks a condition that brings about an uncontrollable event or state. It can be translated as "if" or "when".

Examples:
ニューヨークに行くと面白い店がたくさんある。
If you go to New York there are many interesting shops.

それは先生に聞くとすぐ分かった。
I understood immediately when I asked the teacher.