tsumetai mizu ni remon o irete nomu to, asa wa kibun ga ii desu.

When I drink cold water with lemon in it, I feel good in the morning.

Breakdown of tsumetai mizu ni remon o irete nomu to, asa wa kibun ga ii desu.

• は: topic particle
• です: to be
• を: direct object particle
• 水みず: water

Questions & Answers about tsumetai mizu ni remon o irete nomu to, asa wa kibun ga ii desu.

Why is 冷たい placed directly before 水 with no particle in between?

Because 冷たい is an i-adjective, and i-adjectives can directly modify nouns.

So:

• 冷たい水 = cold water
• 大きい犬 = a big dog
• 新しい本 = a new book

There is no particle needed between the adjective and the noun.

In this sentence, 冷たい水 is just one noun phrase: cold water.

Why is it 水にレモンを入れて and not 水をレモンに入れて?

Because with 入れる, the thing being put in takes を, and the place/container it goes into takes に.

So here:

• レモンを = the lemon is the thing being added
• 水に = the water is what it is being added to

That is why:

• 水にレモンを入れる = put lemon into water

If you said 水をレモンに入れる, it would mean put water into a lemon, which is not what this sentence means.

What exactly does に mean in 水に here?