اذا بدك تقطع الشارع، امشي دغري لهديك الاشارة.

It is specifically Levantine colloquial Arabic.

A few clear clues are:

• بدك = a very common Levantine way to say you want
• دغري = colloquial Levantine for straight / directly
• هديك = a colloquial demonstrative meaning that

In Modern Standard Arabic, the sentence would be phrased differently, for example with words like أردت or تعبر and تلك.

إذا means if for a real or likely situation.

So here, إذا بدك تقطع الشارع means something like if you want to cross the street.

لو is usually used more for hypothetical, unreal, or contrary-to-fact situations. So إذا is the natural choice here because the speaker is giving a practical instruction for a real situation.

بدك means you want or sometimes you need, depending on context.

It is made of:

• بدّ = want / desire / need
• -ك = you singular

So:

• بدك = you want to a man
• بدِّك = you want to a woman
• بدكن = you all want

In this sentence, it is addressing one person, most likely masculine singular.

Because after بدك meaning want to, Levantine normally uses the bare imperfect verb, without the بـ prefix.

So you get:

• بدك تقطع = you want to cross
• بدك تروح = you want to go
• بدك تدرس = you want to study

The بـ prefix is often used for the ordinary present or habitual sense, but after بدك it is usually dropped.

Literally, the root behind تقطع is related to cutting, but in everyday Levantine تقطع الشارع is a very normal way to say cross the street.

So yes, it is idiomatic and natural.

You may also hear تعبر الشارع, which also means cross the street, but تقطع الشارع is very common in spoken Arabic.

A common Levantine pronunciation is roughly:

teʔṭaʕ

A few notes:

• تـ = te-
• ق in many Levantine accents is pronounced like a glottal stop ʔ, the sound in the middle of English uh-oh
• ط is an emphatic t
• ع is the deep Arabic sound ʕ, which has no exact English equivalent

So a learner-friendly approximation is:

te-ta-a with a little catch in the throat after the first syllable, but if you want to sound more accurate, aim for teʔṭaʕ.

Because the ل of the definite article الـ assimilates before certain letters called sun letters.

Since ش is a sun letter, الشارع is pronounced roughly:

ish-shāreʕ or esh-shāreʕ

not el-shāreʕ.

So the l sound disappears, and the sh sound gets doubled.

This is a general pronunciation rule in Arabic, not something unique to this sentence.

امشي is the imperative of walk / go on foot, and دغري means straight, directly, or sometimes right away, depending on context.

In this sentence, امشي دغري means:

• walk straight
• go straight ahead
• keep going straight

So دغري here is about direction, not time.

لهديك is made of:

• لـ = to / toward
• هديك = that for a feminine noun

So لهديك means to that or toward that.

It is هديك, not هداك, because إشارة is a feminine noun, and demonstratives in Arabic usually agree with the noun’s gender.

So:

• هداك = that, masculine
• هديك = that, feminine

Since إشارة is feminine, هديك الإشارة is the correct match.

الإشارة can mean signal, sign, or traffic light / indicator, depending on context.

In this sentence, because the context is crossing the street, it most likely means:

• the traffic light
• the pedestrian signal
• possibly that sign/signal over there

So the exact English word depends on the situation, but the Arabic is very natural.

To a woman, you would usually say:

اذا بدِّك تقطعي الشارع، امشي دغري لهديك الاشارة.

The main visible change is:

• تقطع → تقطعي

To several people:

اذا بدكن تقطعوا الشارع، امشوا دغري لهديك الاشارة.

The changes are:

• بدك → بدكن
• تقطع → تقطعوا
• امشي → امشوا

So the sentence changes mainly in the you forms.