kyou ha hayaku netai desu.

I want to go to bed early today.

Breakdown of kyou ha hayaku netai desu.

• は: topic particle
• です: to be
• 今きょ日う: today
• 〜たい: to want to
• 早はやく: early
• 寝ねる: to sleep; to go to bed

Questions & Answers about kyou ha hayaku netai desu.

What does は do in 今日 は 早く 寝たい です? Why not が or nothing?

は marks 今日 (today) as the topic of the sentence: “As for today, I want to go to bed early.”

• が would mark something as the grammatical subject or as something being contrasted/focused, and 今日が早く寝たいです is not natural.
• Leaving out は (今日早く寝たいです) is possible in casual speech, but feels a bit abrupt. Using は makes the sentence feel neatly framed: “Today, (at least), I want to sleep early.”

Why is it 早く and not 早い?

早い (hayai) is an i-adjective meaning early/fast.
早く (hayaku) is its adverb form, meaning early/quickly.

In Japanese, verbs are usually modified by adverbs, not adjectives:

• 早い 寝たい → incorrect / unnatural (adjective before verb)
• 早く 寝たい → correct (adverb before verb)

So 早く 寝たい literally means “want to sleep early” or “want to go to bed early”.

What exactly is 寝たい? Is it a verb form or an adjective?

寝たい (netai) comes from the verb 寝る (neru, to sleep / to go to bed).

• Take the verb stem: 寝る → 寝
• Add たい: 寝 + たい → 寝たい

Grammatically, ～たい behaves like an i-adjective:

• Dictionary form: 寝たい (want to sleep)
• Negative: 寝たくない (don’t want to sleep)
• Past: 寝たかった (wanted to sleep)
• Past negative: 寝たくなかった (didn’t want to sleep)

So it’s a “desire” form built from a verb, but conjugated like an i-adjective.

Why is です added after 寝たい? Isn’t 寝たい already complete?

寝たい by itself is a complete predicate: “I want to sleep.”

Adding です:

• Makes the sentence polite.
• Softens the tone: 寝たい (plain) vs 寝たいです (polite, neutral, more appropriate to say to non‑close friends, coworkers, etc.).

So:

• 今日 は 早く 寝たい。 → Plain: “I want to go to bed early today.” (used with friends, diary, etc.)
• 今日 は 早く 寝たい です。 → Polite: “I want to go to bed early today.” (to people you speak politely to)

Grammatically, you can think of たい acting like an adjective, and です is the polite copula (similar to “am/is/are” in English politeness terms).

Where is the “I” in this sentence? Why is 私 not used?

Japanese often omits the subject if it’s clear from context.

In 今日 は 早く 寝たい です, the understood subject is 私 (I):

• Full version: （私は）今日 は 早く 寝たい です。
• Natural spoken/written form: 今日 は 早く 寝たい です。

You usually only add 私(は) if:

• You need to contrast with someone else:
  
  • 私は 今日 は 早く 寝たい です。 (As for me, I want to go to bed early today.)
• The subject isn’t clear from context and you must specify who.

What’s the difference between 寝る and 眠る? Could I say 眠りたい instead of 寝たい?

Both relate to sleep, but their usage is a bit different.

• 寝る (neru) = to go to bed / lie down to sleep / sleep in everyday life.

  • Very common in daily speech.
  • 寝たい = “I want to go to bed / I want to sleep.”

• 眠る (nemuru) = to sleep in a more literal or sometimes literary sense, often focusing on the state of being asleep.

  • Also used figuratively: “a volcano sleeps”, “data sleeps in a file,” etc.
  • 眠りたい is grammatically correct, but less common in everyday casual “I want to crash early” type talk.

In normal conversation about going to bed, 寝たい is strongly preferred.

Can the word order be changed? For example, can I say 早く 今日 は 寝たい です?

Japanese word order is somewhat flexible, but it has natural preferences.

The most natural order here is:

• 今日 は 早く 寝たい です。

You can move adverbs and topics around, but some orders sound awkward or overly marked. For example:

• 早く 今日 は 寝たい です。 – grammatically possible, but sounds a bit unnatural; it puts a weird focus on 早く first.
• 今日 は 寝たい です、早く。 – sounds like you’re adding 早く as an afterthought: “Today I want to sleep… early, I mean.”

For learners, stick with: [Topic] は [manner/time] [verb/たい] です → 今日 は 早く 寝たい です.

How do I say “I don’t want to go to bed early today” or “I wanted to go to bed early today”?

Since 寝たい behaves like an i-adjective, you conjugate it like one.

From 寝たい:

• Negative (don’t want to sleep):

  • 寝たくない → “don’t want to sleep”
  • 今日 は 早く 寝たくない です。
    → “I don’t want to go to bed early today.”

• Past (wanted to sleep):

  • 寝たかった → “wanted to sleep”
  • 今日 は 早く 寝たかった です。
    → “I wanted to go to bed early today.”

• Past negative (didn’t want to sleep):

  • 寝たくなかった → “didn’t want to sleep”
  • 昨日 は 早く 寝たくなかった です。
    → “I didn’t want to go to bed early yesterday.”

Does 今日 は have any special nuance, like contrast (“at least today”)?

Yes, は can carry a contrastive nuance, depending on context.

今日 は 早く 寝たい です can be understood in two ways:

1. Neutral topic:

   • “Today, I want to go to bed early.” (simple statement about today)

2. Slight contrast:

   • “Today (at least), I want to go to bed early.”
   • Implies: maybe usually you don’t go to bed early, but today is different.

Whether listeners feel the contrast depends on context and intonation. In isolation, it’s usually heard as a simple, neutral “Today, I want to go to bed early.”

Is 早く modifying 寝たい or 寝る? What exactly is “early” here?

Conceptually, 早く modifies the underlying action 寝る (to go to bed / sleep):

• Underlying idea: 早く 寝る → “to go to bed early”
• Then with desire: 早く 寝たい → “want to go to bed early”

So 早く tells us when / how the action of “going to bed” happens: at an early time, not “quickly wanting.”

It does not mean “I quickly want to sleep”; it means “I want to sleep earlier than usual / early (in the evening, at night).”