Learn Hardcore Japanese: mou itido yukkuri hanasite kudasai.

“Already” – e.g.
- もう食べました。 = “I already ate.”
“More / another / again” (one more time) – when used with 一度, 一回, etc.
- もう一度 = “one more time,” “once more,” “again”

In もう一度ゆっくり話してください, もう is working together with 一度 to mean “one more time” or “once more.” It is not “already” here.

What is the nuance of 一度 here? How is it different from 一回?

Both 一度 (いちど) and 一回 (いっかい) can mean “one time / once,” and in everyday conversation もう一度 and もう一回 are often interchangeable.

Nuance:

一度
- Slightly more neutral or formal-sounding.
- Common in set phrases like もう一度言ってください (“Please say it once more.”)
一回
- Slightly more casual/colloquial.
- Common in everyday speech: もう一回やって (“Do it one more time.”)

In this sentence, もう一度 is a polite, standard way to say “once more.”
You could say もう一回ゆっくり話してください in casual conversation, but 一度 sounds a bit more “textbook polite.”

Why is there no word for “you” in this sentence? How do we know it’s “you, please speak…”?

Japanese often omits subjects and even objects when they are obvious from context. Here:

The situation is presumably: you are talking to someone and asking them to repeat themselves.
From context, the listener understands that they are the one who should “speak slowly again.”

So instead of saying “You, please speak slowly again,” Japanese just says:

もう一度ゆっくり話してください。
Literally: “Once more, slowly, speak, please.”

If you really wanted to add “you” explicitly, you could say:

あなたはもう一度ゆっくり話してください。

…but this sounds unnatural or overly pointed in most real situations. Normally, you just omit the subject in Japanese.

What grammar form is 話して and why is it used here?

話して is the te-form of the verb 話す (“to speak, to talk”).

Dictionary form: 話す
Te-form: 話して

In this sentence, the te-form is used because it connects to ください to make a polite request:

話して + ください → 話してください
= “please speak / please talk”

So the pattern is:

[verb in te-form] + ください → polite request: “Please do [verb].”
e.g. 見てください (please look), 読んでください (please read), 待ってください (please wait).

What exactly is ください? Is it a verb by itself?

Yes. ください comes from the verb くださる, a polite/honorific verb meaning “to give (to me/us).”

In modern usage:

As part of [te-form] + ください, it functions like a fixed polite request expression:
話してください = “Please speak.”
When used as a stand-alone verb (more clearly seen in non-te-form patterns), it literally means “please give me (something)” but that’s not what’s happening here.

In the pattern you’re learning, just think of:

[verb-te] + ください = “please do [verb].”

It’s polite but not super formal; it’s common and safe to use with strangers, store staff, teachers, etc.

How polite is 話してください compared to other ways of asking?

話してください is polite, but not the most formal. A rough scale:

Very casual:
- 話して (“Talk.” / “Speak.” to close friends, family, kids; can be a soft request or just an instruction depending on tone.)
Polite (standard):
- 話してください。 (“Please speak.”) – what you have here.
More polite/softer:
- 話してくれますか。
- 話してくれませんか。
- 話していただけますか。
  These are closer to “Could you (please) speak…?” and sound softer/more deferential.

Your sentence もう一度ゆっくり話してください is appropriate for most polite situations, like talking to a teacher, a store clerk, or a stranger.

What is ゆっくり exactly? Is it an adverb or an adjective?

ゆっくり is an adverb-like word meaning “slowly,” “at a relaxed pace.”

In ゆっくり話してください, it modifies the verb 話す, so it works like an adverb:
“Please speak slowly.”

It can also be used more freely, almost like a phrase:

ゆっくりしてね。 = “Take it easy / Relax.”
ゆっくり休んでください。 = “Please rest well / take your time resting.”

So you can think of ゆっくり as “slowly, at leisure, unhurriedly.”

How is ゆっくり different from おそく (from 遅い) for “slowly / late”?

Both are related to slowness, but they’re used differently:

ゆっくり = “slowly, at an easy/relaxed pace”
- Focuses on how something is done (pace, not speed limit or lateness).
- e.g. ゆっくり話してください。 – “Please speak slowly.”
おそく is the adverb form of 遅い = “late/slow.”
- Often refers to lateness (time), or “slow” as in “not fast enough,” sometimes with a negative nuance.
- e.g. 遅く来ないでください。 – “Please don’t come late.”

If you want to ask someone to speak more slowly, ゆっくり is the natural choice, not おそく.

Can I change the word order, like ゆっくりもう一度話してください? Does it sound natural?

Japanese word order is relatively flexible for adverbs like もう一度 and ゆっくり, but not all orders are equally natural.

Most natural patterns here:

もう一度ゆっくり話してください。
もう一度、ゆっくり話してください。 (with a pause/comma)

You can say something like:

ゆっくりもう一度話してください。

and people will understand, but it sounds slightly less standard/natural than putting もう一度 first. In this sentence, starting with もう一度 (or putting it right after the topic) is the most common.

Could I say 言ってください instead of 話してください? What’s the difference?

Yes, and in fact, 言ってください is often more common in this kind of request.

話す = “to speak, to talk” (general act of talking)
- もう一度ゆっくり話してください。
  → “Please speak slowly once more.” (a bit general)
言う = “to say (specific words/phrases)”
- もう一度ゆっくり言ってください。
  → “Please say it again, slowly.”

If the problem is that you didn’t catch what someone just said, native speakers often say:

もう一度ゆっくり言ってください。

Your textbook sentence with 話して is correct, but with a real person, 言ってください might feel more natural in many contexts.

Why are there spaces between the words in the Japanese sentence? I thought Japanese doesn’t use spaces.

You’re right: normal Japanese writing does not use spaces between words. Textbooks and beginner materials often add spaces to help learners see word boundaries:

Teaching format: もう　一度　ゆっくり　話して　ください。
Natural native writing: もう一度ゆっくり話してください。

So the spaces are just a teaching aid. In real Japanese texts (books, signs, messages), you won’t see spaces like this.

How would I say this more casually to a friend?

To a close friend or someone of the same age/status in a casual situation, you can drop ください and slightly change the wording:

もう一回ゆっくり話して。
もう一度ゆっくり話して。

一回 sounds a bit more colloquial than 一度, but both are fine.

The lack of ください makes it casual. Your tone of voice will determine whether it’s gentle (“Could you say it again slowly?”) or more direct (“Say it again slowly.”).