What's the difference between 冷たい (tsumetai) and 寒い (samui)?

First up, 寒い (samui) is the perfect word to describe cold weather or the feeling of being cold, e.g.

• 今日は寒いですね (kyō wa samui desu ne) - it's cold today, isn't it?
• 昨日は寒くなかったです (kinō wa samukunakatta desu) - it wasn't cold yesterday
• 寒い！(samui!) - I'm cold/it's so cold!

冷たい (tsumetai), on the other hand, is used to describe things that are cold to the touch. For example:

• この水は冷たい (kono mizu wa tsumetai) - this water is cold
• サムさんの手が冷たい (Samu-san no te ga tsumetai.) - Sam's hand is/hands are cold
• 今日は暑すぎる！何か冷たいものが飲みたいなぁ。(Kyō wa atsusugiru! Nani ka tsumetai mono ga nomitai naa.) - It's too hot today. I want something cold to drink.

You can also extend 冷たい (tsumetai) to describing people!

• あの人は冷たい (ano hito wa tsumetai) - that person is [emotionally] cold
• 冷たくしないで (tsumetaku shinaide) - don't be cold to me/don't give me the cold shoulder
• 会議中にギャグを言ったら、周りの人から冷たい目で見られた (Kaigichuu ni gyagu wo ittara, mawari no hito kara tsumetai me de mirareta) - I made a joke in a meeting and got cold looks from the people around me

When might I use 冷たい (tsumetai)?

Although 冷たい (tsumetai) is all about things being cold, it's not all about the cold months of the year! In fact, it's a really handy word for in the summer when you want a nice cool drink or something cold to eat (black sesame ice cream, anyone?).

Although it can be easy to mix up 冷たい (tsumetai) and 寒い (samui) - I still do it 10yrs into learning Japanese! - adding 冷たい (tsumetai) to your vocab can really add to the range of situations you can talk about in Japanese.