אם הכלל הזה לא ברור לך, תשאלי שוב לפני שהשיעור ייגמר.

Hebrew very often uses the future tense to give a command, instruction, or suggestion, especially in everyday speech.

So תשאלי is grammatically future, second person feminine singular, but in context it means ask.

• שאלי = direct imperative: Ask!
• תשאלי = literally you will ask, but often used as ask

Both are correct, but תשאלי can sound a little more natural or less abrupt in many situations.

The ending -י here marks second person feminine singular.

So the speaker is addressing one female student.

Related forms:

• תשאל = you will ask / ask (to one male)
• תשאלי = you will ask / ask (to one female)
• תשאלו = you will ask / ask (to more than one person)

So this sentence is specifically said to a woman or girl.

Because ברור works with the preposition ל־ when you say something is clear to someone.

So:

• ברור לי = clear to me
• ברור לך = clear to you
• ברור לו/לה = clear to him/her

Hebrew expresses this idea as clear to you, not clear you.

That is why לך is correct here:

• לא ברור לך = it isn’t clear to you

Because ברור agrees with הכלל, and הכלל is a masculine singular noun.

• הכלל = the rule (masculine singular)
• therefore: ברור = clear (masculine singular)

If the noun were feminine, you would use ברורה:

• הנקודה הזאת לא ברורה לי = this point is not clear to me

So ברור matches הכלל, not the person being addressed.

In Hebrew, when this/that modifies a noun directly, it usually comes after the noun.

So:

• הכלל הזה = this rule
• השיעור הזה = this lesson
• הספר הזה = this book

This is the normal Hebrew pattern for noun + this/that.

By contrast, זה הכלל means something more like this is the rule.
So the word order changes the structure of the sentence.

That is a very normal Hebrew pattern.

אם means if, and the condition can be stated with a present-tense description:

• אם הכלל הזה לא ברור לך = if this rule is not clear to you

Then the main clause can give a result, instruction, or command:

• תשאלי שוב = ask again

So the overall structure is:

• If X is the case, do Y

This works very much like English:

• If you don’t understand, ask again.

שוב means again.

So:

• תשאלי שוב = ask again

It tells the listener to ask one more time if necessary.
It is a very common word in Hebrew.

Examples:

• תגיד שוב = say it again
• תנסי שוב = try again
• קרא שוב = read again

Because לפני is followed here by a full clause: the lesson ends.

• לפני = before
• ש־ = that / introducing the following clause
• השיעור ייגמר = the lesson will end

So:

• לפני שהשיעור ייגמר = before the lesson ends

This is very common in Hebrew:

• אחרי שהגעתי = after I arrived
• לפני שהוא הלך = before he left

If there were no full clause after לפני, you would not need ש־:

• לפני השיעור = before the lesson
• לפני סוף השיעור = before the end of the lesson

Because ייגמר means will end / will be finished, while יגמור usually means will finish (something).

Here, השיעור is not actively finishing an object. The lesson itself is simply ending. So Hebrew uses נגמר in the future:

• השיעור ייגמר = the lesson will end

Compare:

• המורה יגמור את השיעור = the teacher will finish the lesson
• השיעור ייגמר = the lesson will end

So the sentence uses the intransitive idea: the lesson comes to an end.

They are close in meaning, but not exactly the same in tone.

• אם הכלל הזה לא ברור לך = if this rule is not clear to you
• אם את לא מבינה את הכלל הזה = if you do not understand this rule

The sentence with ברור לך sounds a bit less direct and a little more neutral. It focuses on the clarity of the rule, not on the listener’s ability.

Teachers often use this kind of wording because it can sound gentler:

• not you don’t understand
• but it isn’t clear to you

So both are possible, but לא ברור לך is often a very natural teaching/classroom phrasing.