اگر زود نروی، به موقع به کلاس نمیرسی.

Because after اگر in this kind of real future condition, Persian often uses the present subjunctive.

• بروی = you go / you would go
• نروی = you do not go

So:

• اگر زود نروی = if you don’t go early / if you don’t leave early

By contrast, نمی‌روی is the ordinary present indicative: you are not going / you don’t go.

In conditional sentences about what will happen, Persian commonly prefers:

• اگر + subjunctive
• then a normal present verb in the result clause

So this sentence is very natural:

• اگر زود نروی، به موقع به کلاس نمی‌رسی.

Yes. نروی is the negative present subjunctive, second person singular, from the verb رفتن (to go).

A simple breakdown:

• verb stem: رو / رو-
• subjunctive marker: بـ
• 2nd person singular ending: -ی
• positive form: بروی
• negative form: نروی

In negative subjunctive, the نـ replaces the بـ, so you get:

• بروی → نروی

This is why you do not say نبروی.

The second clause is the result of the condition:

• به موقع به کلاس نمی‌رسی = you won’t get to class on time

Persian often uses the present indicative here, even when English uses will:

• نمی‌رسی literally looks like you do not arrive/reach
• but in context it means you will not arrive / you won’t make it

So the pattern is often:

• اگر + subjunctive, present indicative

Example:

• اگر درس نخوانی، قبول نمی‌شوی.
• If you don’t study, you won’t pass.

زود means early or soon, depending on context.

In this sentence, it means early:

• زود رفتن = to go/leave early

So اگر زود نروی means:

• if you don’t leave early
• literally, if you don’t go early

English often says leave early, while Persian simply uses go early.

به موقع means on time, in time, or at the proper time.

It is a fixed expression:

• به = to / at / in
• موقع = time / occasion / proper moment

Together:

• به موقع = on time

So:

• به موقع می‌رسم = I arrive on time
• به موقع نمی‌رسی = you won’t arrive on time

This is just how Persian expresses the idea; it is best learned as a chunk.

Because the two به phrases do different jobs:

• به موقع = on time
• به کلاس = to class

So the sentence is structured like:

• به موقع = adverbial phrase describing when/how
• به کلاس = destination

That is why both are needed:

• اگر زود نروی، به موقع به کلاس نمی‌رسی.
• If you don’t leave early, you won’t get to class on time.

Because کلاس here is not a direct object. It is the destination of the verb رسیدن (to arrive/reach).

With رسیدن, Persian normally uses به:

• به خانه رسیدن = to arrive home
• به مدرسه رسیدن = to arrive at school
• به کلاس رسیدن = to get to class

را marks a definite direct object, but کلاس here is not an object being acted on. It is the place you are arriving at.

The sentence is:

• اگر زود نروی، به موقع به کلاس نمی‌رسی.

A rough breakdown:

• اگر = if
• زود = early
• نروی = you don’t go / you don’t leave
• به موقع = on time
• به کلاس = to class
• نمی‌رسی = you don’t arrive / you won’t get there

So Persian puts the verb at the end of each clause, which is very typical.

You can think of it as:

• If + early + you-don’t-go, on-time + to-class + you-don’t-arrive

That final-verb pattern is one of the biggest word-order differences from English.

A learner-friendly pronunciation would be:

• نروی ≈ na-ravi
• نمی‌رسی ≈ na-mi-resi

Full sentence:

• agar zud naravi, be moghe' be kelas nemiresi

A few notes:

• اگر = agar
• زود = zud
• نروی = na-ravi
• به موقع = be moghe'
• به کلاس = be kelas
• نمی‌رسی = na-mi-resi

In normal speech, the vowels may sound a little shorter or more connected, but this is a good practical pronunciation guide.

The standard modern spelling is:

• نمی‌رسی

with a half-space between می and the verb.

So many textbooks and typed texts write:

• می‌رسم
• نمی‌رسم
• می‌رسی
• نمی‌رسی

However, in informal typing, people often omit the half-space and write:

• میرسم
• نمیرسی

So the sentence you saw is understandable, but the more standard spelling is:

• اگر زود نروی، به موقع به کلاس نمی‌رسی.

Yes. It is addressed to one person informally: you singular, like talking to a friend, sibling, classmate, or child.

The endings show that:

• نروی = you (singular, informal) don’t go
• نمی‌رسی = you (singular, informal) won’t arrive

If you wanted to speak more formally or to more than one person, you would use -ید forms:

• اگر زود نروید، به موقع به کلاس نمی‌رسید.

That can mean:

• if you (formal singular / plural) don’t leave early, you won’t get to class on time

Not in this exact sentence, because the clause is negative.

You would have:

• positive: اگر زود بروی = if you go early
• negative: اگر زود نروی = if you don’t go early

So بروی and نروی are a pair:

• بروی = you go
• نروی = you do not go

You would not mix بری into this exact wording unless you were using a colloquial variant in speech. In standard writing, بروی / نروی is the expected form.

It looks like present tense on the surface, but in context it refers to the future.

So:

• اگر زود نروی = if you don’t leave early
• به موقع به کلاس نمی‌رسی = you won’t get to class on time

This is very common in Persian. Present forms are often used for future meaning when the context makes it clear.

English usually needs will / won’t, but Persian often does not.