اگر هوا خیلی گرم است، پنکه را روشن کن.

اگر means if. It introduces a condition, just like if in English:

• اگر هوا خیلی گرم است = if the weather/air is very hot

So the whole sentence has a typical if X, do Y structure.

هوا can mean both air and weather, depending on context. In sentences about temperature, it often refers to the general atmosphere or weather:

• هوا گرم است = the weather is hot / it is hot

This is very natural in Persian. English usually says it’s hot, but Persian often uses هوا.

است is the formal written form of is. So:

• گرم است = is hot

In careful writing, است is common. In everyday speech, it is often shortened or dropped:

• گرمه = colloquial form of گرم است

So in conversation, many speakers would say something closer to:

• اگر هوا خیلی گرمه، پنکه را روشن کن.

Both are correct; است just sounds more formal or written.

خیلی means very. It strengthens the adjective that follows it:

• خیلی گرم = very hot

It comes before the adjective, just like in English:

• very hot
• خیلی گرم

را marks the definite direct object. It shows that پنکه is the thing being acted on.

• پنکه را روشن کن = turn on the fan

Here, the fan is the object of the action turn on, so Persian marks it with را.

A useful point:

• In formal writing, it is written را
• In speech, it is often pronounced ro

So spoken Persian often sounds like:

• پنکه رو روشن کن

Persian often uses compound verbs. Here:

• روشن = lit, bright, on
• کردن = to do / to make

Together, روشن کردن means to turn on.

So روشن کن is the imperative form of روشن کردن, literally something like make it on/lit, but naturally it means turn it on.

This pattern is very common in Persian. Many actions that are one verb in English are expressed with a noun/adjective + a light verb like کردن.

کن is the informal singular imperative of کردن, meaning do! or, in compound verbs, it helps form commands.

In this sentence:

• روشن کن = turn on!

It is addressed to one person in an informal way, like speaking to a friend, child, sibling, or someone you know well.

It is not stated, because Persian usually leaves it out in commands. The verb form already implies the subject.

• روشن کن = (you) turn it on

If you want to include the pronoun for emphasis, you could say:

• تو پنکه را روشن کن

But normally تو is omitted.

You would change the imperative verb from کن to کنید:

• اگر هوا خیلی گرم است، پنکه را روشن کنید.

This is the polite/plural form, used for:

• one person respectfully
• more than one person

So:

• روشن کن = informal singular
• روشن کنید = polite singular or plural

Persian word order is often subject - object - verb, and in commands the object usually comes before the verb as well.

So Persian naturally says:

• پنکه را روشن کن
• literally: the fan turn on

This is normal Persian structure. English puts the verb first in an imperative:

• Turn on the fan

Persian keeps the verb at the end.

پنکه generally means fan, especially an electric fan used to cool a room. The exact type depends on context.

It can refer to:

• a standing fan
• a desk fan
• sometimes a ceiling fan, depending on the situation

If a speaker wants to be more specific, they can add more words, but پنکه by itself usually works fine for fan.

Yes. In everyday conversation, a speaker is likely to make it more colloquial:

• اگه هوا خیلی گرمه، پنکه رو روشن کن.

Changes:

• اگر → اگه
• گرم است → گرمه
• را → رو

This version is very common in speech. The original sentence is perfectly correct, but it sounds more formal or written.

Yes. Persian can also put the main clause first, though the original order is very common:

• پنکه را روشن کن اگر هوا خیلی گرم است.

This still means the same thing. However, putting the if clause first often sounds more natural when introducing the condition before the command:

• اگر هوا خیلی گرم است، ...

That is why the original sentence is a very standard way to say it.