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

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

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

• أن: (subordinating particle)
• الدرس: lesson
• قبل: before
• يفهم: to understand

Questions & Answers about عندما يكون عندي سؤال صعب، أحاول أن أفهمه قبل الدرس.

Why does the sentence begin with عندما? Is it the same as when?

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.

Why is it يكون and not أكون, if the sentence is about I?

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.