לפני שאת חוצה את הכביש, תעצרי ליד מעבר החצייה ותסתכלי על הצומת.

Because the sentence is addressed to one female. In Hebrew, the second person changes for gender, so you is not one single form the way it is in English.

In this sentence:

• שאת
• תעצרי
• תסתכלי

all show that the person being spoken to is feminine singular.

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

• לפני שאתה חוצה את הכביש, תעצור ליד מעבר החצייה ותסתכל על הצומת.

In modern Hebrew, the 2nd-person future is very often used to give instructions or commands, especially in everyday speech.

So:

• תעצרי = stop
• תסתכלי = look

Literally they are future forms, but functionally they often mean you should / you will now do this.

Hebrew also has true imperative forms:

• עצרי
• הסתכלי

But in ordinary spoken Hebrew, the future forms often sound more natural.

שאת is made of two parts:

• ש־ = that
• את = you (feminine singular)

So לפני שאת חוצה literally means something like before that you cross, which in natural English is just before you cross.

This את is a pronoun, not the direct-object marker.

That את is a completely different word from the one inside שאת.

In חוצה את הכביש, את is the direct object marker. Hebrew uses it before a definite direct object, meaning a direct object with the or something otherwise definite.

So:

• חוצה כביש = crossing a road
• חוצה את הכביש = crossing the road

This את usually has no direct translation in English.

חוצה is the present-tense form of לחצות (to cross).

With this verb, the singular present form חוצה is the same for:

• masculine singular
• feminine singular

So by itself, חוצה does not tell you whether the subject is male or female. You know it is feminine here because of שאת.

This is normal for some Hebrew verbs: the singular present form can be identical for both genders.

After לפני ש־ (before that / before), Hebrew very often uses a clause like שאת חוצה. This is a normal everyday way to say before you cross.

You may also hear:

• לפני שתחצי את הכביש

That is also possible. The version with את חוצה is very common in spoken Hebrew and feels immediate and natural in instructions.

A learner may expect something like תעצורי, because the infinitive is לעצור, but Hebrew verb patterns do not always keep the same internal vowels or letters in every form.

So:

• infinitive: לעצור
• feminine singular future / command-like form: תעצרי

The missing ו is not unusual. Hebrew conjugation often changes the shape of the word when you move from the infinitive to future forms.

This is a construct chain (סמיכות) in Hebrew.

• מעבר = crossing / passage
• חצייה = crossing
• מעבר החצייה = the crosswalk / pedestrian crossing

In a construct chain, the first noun usually does not take ה־, even when the whole phrase is definite. The definiteness is shown on the second noun:

• מעבר חצייה = a crosswalk
• מעבר החצייה = the crosswalk

So מעבר החצייה is correct.

כביש usually refers to the roadway, the part where cars drive.

רחוב is street, but it can refer more broadly to the street as a location or address.

When talking about crossing where vehicles travel, כביש is very natural:

• לחצות את הכביש = to cross the road

So in road-safety language, כביש is often the better word.

ליד means next to / by / beside.

So תעצרי ליד מעבר החצייה means stop by the crosswalk, not in the crosswalk.

That distinction matters:

• ליד מעבר החצייה = near the crosswalk
• במעבר החצייה = in/on the crosswalk

Here the idea is: stop near it first, then look, then cross.

Because להסתכל normally goes with the preposition על when you say what someone is looking at.

So:

• להסתכל על משהו = to look at something

Even though English uses at, Hebrew uses על.

Examples:

• תסתכלי על הכביש = look at the road
• תסתכלי על הצומת = look at the intersection

Yes. A more strictly imperative version would be:

• לפני שאת חוצה את הכביש, עצרי ליד מעבר החצייה והסתכלי על הצומת.

That is grammatically correct, but many speakers would naturally prefer:

• תעצרי
• תסתכלי

In modern spoken Hebrew, future forms often sound more conversational and less formal than the classic imperative.