إذا لم تفهمي السؤال، اسألي الأستاذة بعد الدرس.

That -ي shows the sentence is addressed to one female: you (feminine singular).

• تفهمي = you understand / you understand not here after لم
• اسألي = ask! said to one woman or girl

If you were speaking to a man, you would say:

• إذا لم تفهم السؤال، اسأل الأستاذ بعد الدرس.

So the sentence is specifically talking to a female student.

Because لم is the normal particle used to negate a verb in the jussive form, and it often appears in conditions like this.

So:

• لم تفهمي = you did not understand / you do not understand in this conditional sense
• لا تفهمي would usually sound like do not understand!, which is a negative command, not what is meant here

In this sentence, إذا لم تفهمي السؤال means if you do not understand the question.

Great question. The full present-tense form for you (feminine singular) understand is:

• تفهمين

But after لم, the verb must go into the jussive. For this kind of verb form, called one of the five verbs (الأفعال الخمسة), the final ن is dropped.

So:

• normal: تفهمين
• after لم: تفهمي

This is a very common pattern in Arabic grammar.

It comes from the verb:

• فَهِمَ = to understand

Its present tense is:

• يَفْهَمُ = he understands

From that you get:

• تَفْهَمِينَ = you (feminine singular) understand
• after لم: تَفْهَمِي

So تفهمي is not a separate dictionary word; it is a changed form of the verb فهم.

إذا means if in a condition like this.

So:

• إذا لم تفهمي السؤال = if you do not understand the question

In MSA, إذا is often used for real or expected situations. It is very common in instructions and general advice.

You may also have seen إن for if. Both can mean if, but إذا often sounds more like a likely or practical condition in contexts like this.

اسألي is the command form addressed to one female, meaning ask!

It comes from the verb:

• سَأَلَ = to ask

The masculine singular command is:

• اسأل

The feminine singular command is:

• اسألي

So the sentence says to a female student:

• Ask the teacher after the lesson.

This final -ي again shows that the command is for one female.

It is pronounced roughly:

• is-'a-lī

A more careful breakdown is:

• اِسْ
  • أَ
    • لِي

The root contains a hamza: س-أ-ل, so you hear a little catch in the middle.

Learners often want to smooth it out too much, but the hamza is really there.

Because Arabic verbs already include the subject.

In تفهمي and اسألي, the ending tells you the subject is:

• you (feminine singular)

So adding أنتِ is usually unnecessary unless you want extra emphasis.

Arabic often leaves subject pronouns unstated because the verb already gives that information.

السؤال means the question, not just a question.

In this sentence, it refers to a specific question already known from the context, such as the question in class, on the board, or in an exercise.

So:

• سؤال = a question
• السؤال = the question

English might sometimes say the question or a question depending on context, but Arabic here uses the definite form naturally.

No. In Arabic, the verb سأل can take the person directly as its object.

So:

• اسألي الأستاذة = ask the teacher

This is similar to English, where we also say ask the teacher, not ask to the teacher.

Arabic can also use عن when talking about the thing asked about:

• سألتُ الأستاذةَ عن السؤال = I asked the teacher about the question

But in your sentence, الأستاذة is simply the person being asked.

Both can mean female teacher, depending on context.

• الأستاذة often means female teacher, instructor, or sometimes professor
• المعلمة usually means female schoolteacher

So الأستاذة is a perfectly natural choice, especially in formal or educational contexts.

It can mean either, depending on context.

• بعد = after
• الدرس = the lesson, the class, or the session

So in a classroom setting, بعد الدرس is very naturally understood as:

• after the lesson
• after class

English may choose either translation depending on what sounds more natural.

Arabic often does not need a separate word for then in a basic conditional sentence.

The structure itself already shows the sequence:

• إذا لم تفهمي السؤال، اسألي الأستاذة بعد الدرس.

That naturally means:

• If you do not understand the question, ask the teacher after the lesson.

English sometimes adds then, but Arabic often leaves it implied.

You would change the feminine singular forms to masculine singular:

• إذا لم تفهم السؤال، اسأل الأستاذ بعد الدرس.

Changes:

• تفهمي → تفهم
• اسألي → اسأل
• الأستاذة → الأستاذ if the teacher is male

If the teacher were still female, you could say:

• إذا لم تفهم السؤال، اسأل الأستاذة بعد الدرس.

Yes, it is perfectly normal Modern Standard Arabic.

It is clear, grammatical, and suitable for:

• textbooks
• classroom instructions
• school materials
• formal speech

In everyday spoken Arabic, the exact wording might change depending on the dialect, but in MSA this sentence is completely natural.

The comma is helpful, but not absolutely essential.

It separates the conditional clause from the command:

• إذا لم تفهمي السؤال، اسألي الأستاذة بعد الدرس.

Arabic punctuation is used in modern writing, especially in educational or formal texts, but you may sometimes see similar sentences written without a comma. The meaning would still be clear.