عندما يكون عندي سؤال صعب، أحاول أن أفهمه قبل الدرس.

Yes. عندما is a common formal way to say when in Modern Standard Arabic.

In this sentence, عندما introduces a time clause:

• عندما يكون عندي سؤال صعب = when I have a difficult question

It is often used for:

• habitual situations: when(ever)
• general time relationships
• formal written style

A close alternative is إذا, but عندما often sounds a bit more formal and neutral in MSA.

This is a very common question.

The verb يكون here does not mean I am. It agrees with the noun سؤال later in the clause.

The structure is literally closer to:

• when there is, with me, a difficult question

So:

• يكون = it is / there is
• عندي = with me / in my possession
• سؤال صعب = a difficult question

The real grammatical subject of يكون is سؤال:

• سؤال is singular masculine
• so the verb is يكون (3rd person masculine singular)

That is why it is not أكون.

عندي literally means at me or with me, and it is very often used to express possession.

It is made of:

• عند = at / with
• ـي = my / me

So:

• عندي سؤال literally = at me is a question
• natural English = I have a question

This is a very common Arabic way to say have, since Arabic does not usually use a separate verb like English to have.

Because in Arabic, possession is usually expressed with a prepositional phrase rather than a dedicated verb like English have.

Common patterns are:

• عندي كتاب = I have a book
• لديّ كتاب = I have a book

So in your sentence:

• عندي سؤال صعب = I have a difficult question

This is one of the first major structural differences English speakers notice in Arabic.

Because the sentence means a difficult question, not the difficult question.

Compare:

• سؤال صعب = a difficult question
• السؤال الصعب = the difficult question

Arabic marks definiteness very clearly. If the noun is indefinite, the adjective is also indefinite:

• سؤال صعب not
• سؤال الصعب

In Arabic, adjectives normally come after the noun they describe.

So:

• سؤال صعب = question difficult = a difficult question

This is the normal order in Arabic:

• noun + adjective

Also, the adjective must match the noun in:

• gender
• number
• definiteness
• case

Here:

• سؤال = singular masculine, indefinite
• صعب = singular masculine, indefinite

So they match correctly.

In normal Arabic writing, short vowels and most case endings are usually not written.

So although you see:

• سؤال صعب

in fully vocalized form it could be:

• سؤالٌ صعبٌ

But in everyday printed Arabic, those endings are usually omitted unless the text is fully vowelled, such as in:

• Qur’anic text
• children’s books
• textbooks
• grammar examples

So the grammar is still there, even when you do not see it.

أن introduces a following verb in the sense of to after many verbs.

So:

• أحاول = I try
• أن أفهمه = to understand it

Together:

• أحاول أن أفهمه = I try to understand it

This is a very common pattern:

• أريد أن أتعلم = I want to learn
• أحب أن أقرأ = I like to read
• أحاول أن أفهم = I try to understand

After أن, the present verb is in the subjunctive. In this verb (أفهم) the form looks the same in writing, but grammatically it is subjunctive.

The ـه is an attached object pronoun meaning him/it.

Here it refers back to:

• سؤال = question

Since سؤال is a masculine singular noun, the pronoun is:

• ـه = it / him

So:

• أفهم = I understand
• أفهمه = I understand it

In this sentence:

• أحاول أن أفهمه = I try to understand it

Because Arabic nouns have grammatical gender.

The noun سؤال is masculine, so any pronoun referring back to it must also be masculine:

• سؤال ... أفهمه

Even though English says it, Arabic still chooses masculine or feminine based on the noun’s grammatical gender.

For example:

• كتاب ... أقرؤه = a book ... I read it
• سيارة ... أشتريها = a car ... I buy it

So the pronoun must match the Arabic noun, not the English translation.

قبل means before.

In:

• قبل الدرس = before the lesson

this is an iḍāfa-type structure:

• قبل = before
• الدرس = the lesson

Literally: before the lesson

This is a very common pattern with words like:

• قبل = before
• بعد = after
• أثناء = during

Examples:

• قبل الامتحان = before the exam
• بعد العمل = after work

Because it refers to the lesson, a specific lesson.

Compare:

• قبل درس = before a lesson
• قبل الدرس = before the lesson

In many contexts, Arabic naturally uses the definite form where English also would:

• before the lesson
• after the meeting
• during the class

So الدرس is definite because the speaker has a specific lesson in mind.

Yes, Arabic word order is often somewhat flexible, but not every change sounds equally natural.

Your sentence is very natural:

• عندما يكون عندي سؤال صعب، أحاول أن أفهمه قبل الدرس.

A close alternative is:

• عندما يكون لديّ سؤال صعب، أحاول أن أفهمه قبل الدرس.

But you would not normally drop يكون and say:

• عندما عندي سؤال صعب ... This sounds incomplete in standard Arabic.

So flexibility exists, but the original structure is standard and natural.

Yes, you could.

Both can express possession:

• عندي = I have
• لديّ = I have

In many contexts:

• عندي sounds a bit more everyday/common
• لديّ often sounds a bit more formal or written

So this is also good MSA:

• عندما يكون لديّ سؤال صعب، أحاول أن أفهمه قبل الدرس.

Both are correct.

Because the Arabic present tense often covers:

• present actions
• habitual actions
• general truths
• near future, depending on context

In this sentence, the meaning is habitual:

• Whenever/When I have a difficult question, I try to understand it before the lesson.

So the present tense fits very naturally:

• يكون
• أحاول
• أفهمه

Arabic often uses the present tense this way in general statements.

In colloquial Arabic, forms like that are common. But in Modern Standard Arabic, after أحاول, the standard form is:

• أحاول أن أفهمه

So for MSA, أن is the expected and correct choice here.

The comma separates the time clause from the main clause:

• عندما يكون عندي سؤال صعب، = when I have a difficult question,
• أحاول أن أفهمه قبل الدرس. = I try to understand it before the lesson.

Arabic punctuation in modern writing often works similarly to English punctuation, especially in formal prose. The comma helps show the pause and structure clearly.