zyuppungo ni kaigi ga hazimarimasu.

It is read じゅっぷんご.

• 十分 here means ten minutes, so it is じゅっぷん.
• 後 here is read ご and means after / later.

So:

• 十分後 = じゅっぷんご = in ten minutes / ten minutes later

A very common beginner confusion is that 十分 can also be read じゅうぶん, but that reading means enough / sufficient, not ten minutes.

後 means after or later.

When it comes after a time amount, it makes an expression meaning:

• X後 = after X / X later / in X

So:

• 十分後 = after ten minutes
• in natural English, often in ten minutes

In this sentence, it tells you when the meeting will begin.

The に marks the time at which something happens.

Here, 十分後に means:

• at/in ten minutes
• literally, something like after ten minutes, at that time

So the structure is:

• 十分後に = in ten minutes
• 会議が始まります = the meeting will begin

Japanese often uses に with a specific time point or a time expression that indicates when an event happens.

Sometimes yes, but に is very natural here.

You may also see:

• 十分後、会議が始まります。

That still makes sense: In ten minutes, the meeting will begin.

However, with 後, using に is very common and clear. For a learner, 十分後に会議が始まります is a very safe and natural pattern.

Because 会議 is the subject of 始まります.

The thing that begins is the meeting, so Japanese marks it with が:

• 会議が始まります = The meeting begins / will begin

This is especially natural because 始まる is an intransitive verb. The meeting itself is the thing undergoing the action of beginning.

If you used は instead, it would change the nuance:

• 会議は始まります = As for the meeting, it will begin

That is possible in the right context, but が is the straightforward choice here.

Because 始まる and 始める are different verbs.

• 始まる = to begin (intransitive)
• 始める = to start something (transitive)

In this sentence, the meeting is not being shown as something that a person starts; it is simply beginning.

So:

• 会議が始まります = The meeting begins
• 部長が会議を始めます = The manager starts the meeting

That is why 始まります is correct here.

It can match all of those, depending on context.

In many everyday situations, if no other reference point is given, 十分後に is naturally understood as:

• in ten minutes
• ten minutes from now

But more literally, it is ten minutes later / after ten minutes.

So the exact English wording depends on the situation, but the Japanese is the same.

The sentence is:

• 十分後に = time expression
• 会議が = subject
• 始まります = verb

So the pattern is:

• [Time] + [subject] + [verb]

A very literal breakdown would be:

• In ten minutes, the meeting begins.

Japanese usually puts time information before the main verb, and the verb comes at the end of the sentence.

Because 〜ます is the polite non-past form.

• 始まる = plain form
• 始まります = polite form

Japanese often uses the polite form in normal conversation, announcements, workplaces, classrooms, and public situations. Since a meeting is a formal topic, 始まります sounds very natural.

The plain version would be:

• 十分後に会議が始まる。

That is less polite and would fit casual speech, narration, or informal writing.

Yes, that is also possible, but the nuance is a little different.

• 十分後に会議が始まります。
  Neutral: The meeting will begin in ten minutes.

• 会議は十分後に始まります。
  Topic-focused: As for the meeting, it will begin in ten minutes.

Using は makes 会議 the topic. Using が simply marks it as the subject of begin. In many contexts, the original sentence with が is the most straightforward.