Learn Hardcore Japanese: mou zikan ga arimasen.

Here, もう with a negative means “no longer / not anymore / not any more.” So もう時間がありません means “There is no time left” or “We don’t have time anymore.” With positive verbs, もう usually means “already” (e.g., もう食べました = I already ate).

Why is the particle が used with 時間 instead of は?

が marks the subject of existence with あります/ありません. You’re stating the bare fact that “time (as a thing) does not exist.” Using は would make 時間 the topic and tends to add contrast (as for time, there isn’t any), shifting the emphasis.

Can I say もう時間はありません? What’s the nuance difference?

Yes. もう時間はありません emphasizes and often contrasts the topic “time,” implying something like “As for time, there isn’t any (though maybe something else remains).” もう時間がありません is a neutral, matter‑of‑fact statement that time does not exist anymore.

Is ありません the same as ないです or ない? What about ございません?

ありません: polite negative of ある; standard and neutral-polite.
ないです: very common in speech; slightly less formal than ありません but perfectly natural in conversation.
ない: plain/casual negative.
ございません: extra-polite business/announcement style.
All mean “do(es) not exist” for inanimate/abstract things; choose based on formality.

Why あります/ありません and not います/いません?

あります/ありません are used for inanimate or abstract things (time, objects, events). います/いません are for living beings (people, animals). 時間 is abstract, so あります/ありません is correct.

Does this mean “I/we don’t have time” or “There is no time”? How do I specify who?

Literally it’s existential: “There is no time (left).” In context, that often implies “I/we don’t have time.” To specify the possessor, add a topic:

私は時間がありません (I don’t have time)
私たちは時間がありません (We don’t have time)

Is もう necessary? What changes if I drop it?

Without もう, 時間がありません means simply “There is no time.” With もう, you add the nuance of “anymore / no longer,” i.e., time has run out.

Can I drop the particle が and say もう時間ありません or もう時間ない?

In casual speech, yes: もう時間ありません (polite-ish) and もう時間ない (casual) are both common. Dropping が is natural in conversation when the subject is obvious.

What’s the plain/casual version of the sentence?

もう時間がない。 You’ll also hear もう時間ない。 in very casual speech.

How do I say “There’s still time”?

Use まだ: まだ時間があります (There is still time). The negative counterpart is もう時間がありません (There is no time anymore). もう and まだ are often contrasted.

Are there other natural ways to say we’re out of time or don’t have enough time?

時間切れです。 (Time’s up.)
時間が足りません。 / 時間が足りない。 (There isn’t enough time.)
もう時間がないです。 / もう時間がない。 (No time left.)
For deadlines: 締め切りに間に合いません。 (We can’t make the deadline.)

Is ありません related to じゃありません? Can I say 時間がじゃありません?

They’re different. じゃありません is the negative copula (used with nouns/adjectives: 学生じゃありません = not a student). ありません is the negative of ある (to exist/have). You cannot say 時間がじゃありません; you must say 時間がありません.

Can I move もう and say 時間がもうありません?

Yes. 時間がもうありません is also natural and means the same thing. Placing もう right before ありません can slightly highlight the “no longer” part, but the difference is minimal.

How do I pronounce each word?

もう: “mou” (long o)
時間: “jikan”
が: “ga”
ありません: “arimasen” Together: “Mou jikan ga arimasen.”

Why are there spaces between the words? Are they necessary?

Spaces are usually added for learners. In normal Japanese writing you wouldn’t use them: もう時間がありません。

Can 時間 also mean “hours”? I’m confused.

時間 by itself means “time” in general. When combined with a number as X時間, it means “X hours” (e.g., 二時間 = two hours). In your sentence, it’s “time” in the general sense.

Can I write 無い instead of ない?

You’ll sometimes see 無い, but many style guides recommend writing the adjective ない in hiragana, especially when it’s the negative of ある. So もう時間がない is the most common spelling.

How would I say this extra politely to a customer?

Use the keigo form: もう時間がございません。 You can soften further with an apology: 申し訳ございませんが、もう時間がございません。