يعمل صديقي في الطيران.

يعمل means he works here.

It is the 3rd person masculine singular form of the verb عَمِلَ / يَعْمَلُ.
In Modern Standard Arabic, this verb can mean things like:

• to work
• to do
• to operate or function in some contexts

In this sentence, the meaning is clearly works.

Because Arabic verbs already include the subject information.

So يعمل by itself already tells you:

• 3rd person = he
• masculine
• singular

That means Arabic often does not need an extra subject pronoun like هو (he), unless you want emphasis.

So:

• يعمل = he works
• هو يعمل = he works / he is working, but with extra emphasis on he

In your sentence, the noun صديقي also names the subject, so adding هو would be unnecessary.

صديقي means my friend.

It is made from:

• صديق = friend
• ـي = my

So:

• صديق = a friend
• صديقي = my friend

This ـي is an attached possessive suffix.

Because the my part is not a separate word in Arabic. It is attached directly to the noun as a suffix.

Compare:

• صديق = friend
• صديقي = my friend
• صديقك = your friend
• صديقه = his friend

This is completely normal in Arabic.

Because possessed nouns in Arabic normally do not take الـ.

So you do not say:

• الصديقي for my friend ❌

Instead, you say:

• صديقي ✅

The noun is already definite because it is possessed: my friend is automatically specific.

Literally, it means in aviation.

Here:

• في = in
• الطيران = aviation, flying, or the aviation field

So the whole phrase means something like:

• in aviation
• in the aviation industry
• in air travel / the airline field

It does not mean he is literally inside a plane at the moment. It describes the field he works in.

In Arabic, fields, industries, and abstract areas are often expressed with a definite noun.

So في الطيران is a natural way to say:

• in aviation
• in the aviation sector

Arabic often uses the definite article in places where English may or may not use the.

So you should think of الطيران here as the normal Arabic way to refer to the field of aviation.

Yes. That is also correct.

Arabic allows both:

• يعمل صديقي في الطيران
• صديقي يعمل في الطيران

The difference is mostly about style and emphasis:

• يعمل صديقي... starts with the verb, which is very common in MSA
• صديقي يعمل... starts with the subject, which can sound a bit more like My friend works...

Both are natural and grammatical.

Yes, the sentence as written refers to a male friend.

You can tell because:

• يعمل is masculine singular
• صديقي usually means my male friend

If you wanted my female friend works in aviation, you would say:

• تعمل صديقتي في الطيران

So the changes are:

• يعمل → تعمل
• صديقي → صديقتي

It is the imperfect form, which often covers the present in Arabic.

In this sentence, it means a present habitual action:

• He works in aviation
• My friend works in aviation

Depending on context, the imperfect can also be used for future meaning, but here it is clearly present.

A careful pronunciation is:

yaʿmalu ṣadīqī fī ṭ-ṭayarān

A few useful notes:

• يعمل = yaʿmalu
• صديقي = ṣadīqī
• في = fī
• الطيران is pronounced aṭ-ṭayarān or after fī, smoothly fī ṭ-ṭayarān

This happens because ط is a sun letter, so the l sound of الـ is not pronounced separately.

So although it is written:

• الطيران

it is pronounced more like:

• aṭ-ṭayarān

Because ط is one of the sun letters.

With sun letters, the ل of الـ is assimilated into the next consonant. So:

• written: الطيران
• pronounced: aṭ-ṭayarān

This is a very common pattern in Arabic.

Examples of the same thing:

• الشمس → ash-shams
• الطالب → aṭ-ṭālib
• الطيران → aṭ-ṭayarān

In full formal vocalization, you could write it as:

يَعْمَلُ صَدِيقِي فِي الطَّيَرَانِ

A few points:

• يَعْمَلُ ends in -u
• فِي makes the following noun genitive
• so الطَّيَرَانِ ends in -i

With صديقي, the case ending is not clearly visible in the usual written form because of the attached ـي suffix.

In normal printed Arabic, these endings are usually not written, and learners often read:

يعمل صديقي في الطيران

without full vowels.

Yes. طيران can refer to:

• flying
• aviation
• the general area of air travel or the airline/aviation sector

In this sentence, because it follows works in, the most natural English interpretation is aviation or the aviation industry, not the act of flying itself.

So the context decides the best translation.