على حسب القياس، الترزي هيقصر الكم.

In Egyptian Arabic, على حسب means according to, depending on, or based on.

So على حسب القياس means something like:

• according to the measurement
• based on the measurements
• depending on the size/measurement

It is a very common phrase in both everyday speech and semi-formal contexts.

Examples:

• على حسب الوقت = depending on the time
• على حسب الفلوس = depending on the money / budget

Yes — both are related, but they are not exactly the same.

• القياس = the measurement / measuring
• المقاس = the size

In this sentence, على حسب القياس suggests according to the measurement that was taken. That fits a tailor very well.

A learner may also hear:

• على حسب المقاس = according to the size

Both can make sense in clothing contexts, but القياس focuses more on the actual measuring.

الترزي means the tailor.

Yes, this is a very common Egyptian word. In Modern Standard Arabic, learners often know خياط for tailor, but in Egyptian speech ترزي is extremely common.

So:

• ترزي = tailor, especially in everyday Egyptian speech
• خياط = tailor/seamster, more standard or widely pan-Arab

Because ت is a sun letter.

When الـ comes before a sun letter, the l sound is absorbed into the next consonant. So:

• written: الترزي
• pronounced: et-terzi or it-terzi in Egyptian-style pronunciation

This is a general rule in Arabic pronunciation.

Other examples:

• الشمس → esh-shams
• الناس → en-nās
• الطالب → et-tāleb

So the spelling stays the same, but the pronunciation changes.

No. In this sentence, هيـ is not the pronoun هي meaning she.

Here, هيقصر is the future form of the verb:

• هيـ = future marker in Egyptian Arabic
• يقصر = he shortens / he will shorten

So هيقصر means he will shorten.

A very common equivalent is حيقصر. In Egyptian, both هـ and حـ can mark the future, depending on speaker and style.

So:

• هيقصر = he will shorten
• حيقصر = he will shorten

That is a very common learner question.

In Egyptian Arabic:

• بيـ often marks the present/habitual
• هـ / حـ often marks the future

So compare:

• الترزي بيقصر الكم = the tailor shortens / is shortening the sleeve
• الترزي هيقصر الكم = the tailor will shorten the sleeve

You normally do not combine them here. So هيقصر is the expected future form.

Because everyday Arabic writing often leaves out short vowels and marks like shadda.

The intended verb here is يقصّر from قصّر, which means to shorten something.

So the fuller reading is closer to:

• هيقصّر

In casual writing, people often write:

• هيقصر

and expect the reader to understand it from context.

This matters because:

• قَصُر / يقصر can mean to become short / be short
• قصّر / يقصّر means to shorten something

In a tailor sentence, the meaning is clearly to shorten.

الكم means the sleeve.

In clothing language, it refers to the sleeve of a shirt, jacket, dress, and so on.

So in this sentence, the tailor is shortening the sleeve.

A useful note: in actual clothing talk, Arabic sometimes uses a singular noun in a general way, especially when the context is obvious. Depending on the situation, the speaker may mean:

• one sleeve specifically
• the sleeve area in general
• the sleeves of the garment, understood from context

It is placed first to set the frame: based on the measurements...

This is very natural in Arabic. The speaker begins with the condition or basis, then gives the main statement.

So:

• على حسب القياس، الترزي هيقصر الكم. = Based on the measurements, the tailor will shorten the sleeve.

You could also hear a different order, such as:

• الترزي هيقصر الكم على حسب القياس.

But putting على حسب القياس first sounds natural and helps emphasize the basis for the decision.

A natural Egyptian-style pronunciation would be roughly:

ʿala ḥasab il-ʔiyās, it-terzi hayʔaṣṣar il-kumm

A few notes:

• القياس is often pronounced with a glottal stop in Egyptian, not a hard q
• الترزي becomes it-terzi / et-terzi because of sun-letter assimilation
• الكم is often pronounced il-kumm, with a doubled m sound

You do not need to pronounce it exactly this way right away, but it helps to know what you may hear.