هل تستطيعين أن تكتبي رقم هاتفك على هذه الصفحة؟

هل is a yes/no question particle. It turns the sentence into a question, like do, does, or simply a rising intonation in English.

So:

• تستطيعين أن تكتبي... = You can write...
• هل تستطيعين أن تكتبي...؟ = Can you write... ?

It does not mean do literally; it just marks the whole sentence as a yes/no question.

Because the speaker is talking to one female.

تستطيعين means you (feminine singular) are able / can.

Compare:

• تستطيعُ = she can
• تستطيعين = you (to one woman/girl) can
• تستطيعُ can also look similar in writing, so the ending matters a lot when fully vocalized

In Arabic, verbs often show the subject inside the verb itself, so you do not need a separate word for you.

It is built into the verb forms:

• تستطيعين = you (feminine singular) can
• تكتبي = you (feminine singular) write

So Arabic does not need a separate pronoun like أنتِ here, although it could be added for emphasis.

أن introduces the following verb, similar to English to in to write.

So:

• تستطيعين أن تكتبي = you can write
• more literally: you are able to write

This is a very common pattern in Arabic:

• أريد أن أذهب = I want to go
• أستطيع أن أفعل = I can do

Because after أن, the verb goes into the subjunctive form.

For this kind of verb, the feminine singular form changes like this:

• تكتبين = you write / you are writing
• أن تكتبي = to write / that you write

So the final -ن drops after أن.

This is a very common grammar point in MSA:

• أنتِ تدرسين = you study
• أريد أن تدرسي = I want you to study

Not exactly. Arabic does not have a separate modal verb exactly like English can. Instead, it often uses a regular verb meaning to be able.

So:

• تستطيعين literally means you are able
• تستطيعين أن تكتبي literally means you are able to write

In natural English, we usually translate that as Can you write... ?

This is an iḍāfa construction, often called a possessive or of structure.

• رقم = number
• هاتف = phone
• رقم هاتفك = the number of your phone = your phone number

A few important things about iḍāfa:

1. The first noun usually does not take ال

   • so it is رقم, not الرقم here

2. The second noun tells you what kind of number it is

   • رقم هاتف = phone number

3. When the second noun has a possessive ending, the whole phrase becomes specific

   • رقم هاتفك = your phone number

In normal Arabic spelling, short vowels are usually not written, so هاتفك can represent:

• هاتفُكَ / هاتفَكَ / هاتفِكَ = your phone when speaking to a male
• هاتفُكِ / هاتفَكِ / هاتفِكِ = your phone when speaking to a female

In this sentence, the surrounding verbs are clearly feminine singular:

• تستطيعين
• تكتبي

So here هاتفك must mean your (feminine singular) phone.

Because الصفحة is a feminine noun.

So Arabic uses:

• هذا = this for masculine nouns
• هذه = this for feminine nouns

Examples:

• هذا الكتاب = this book
• هذه الصفحة = this page

So the demonstrative must match the noun’s gender.

That is the normal order in Arabic:

• هذه الصفحة = this page

In English, we also put this before the noun, so this part is actually quite similar.

Also notice that the noun after هذا / هذه is usually definite:

• هذه الصفحة
• هذا الكتاب

Because ص is a sun letter.

When ال comes before a sun letter, the l sound is not pronounced, and the next consonant is doubled.

So:

• written: الصفحة
• pronounced: aṣ-ṣafḥa

Other examples:

• الشمس → ash-shams
• النور → an-nūr

This is a pronunciation rule; the spelling stays the same.

على usually means on or onto.

So:

• على هذه الصفحة = on this page

That matches the English idea very closely: writing something on a page.

If you used في, that would usually mean in, which is less natural here when talking about physically writing something on the surface of a page.

Yes, it is natural and correct MSA.

It is a polite, straightforward way to say:

• Can you write your phone number on this page?

A few other natural MSA alternatives are possible, for example:

• هل يمكنكِ أن تكتبي رقم هاتفك على هذه الصفحة؟
• هل يمكنكِ كتابة رقم هاتفك على هذه الصفحة؟

These mean almost the same thing. Your original sentence is perfectly good.

A fully vocalized version would be:

هَلْ تَسْتَطيعِينَ أَنْ تَكْتُبِي رَقْمَ هاتِفِكِ عَلَى هذِهِ الصَّفْحَةِ؟

A rough pronunciation guide:

hal tastaṭīʿīna an taktubī raqma hātifiki ʿalā hādhihi aṣ-ṣafḥati?

At the end of a sentence, the final case ending is often not fully pronounced in normal reading, so you may hear something closer to:

... ʿalā hādhihi aṣ-ṣafḥa?

Yes. In everyday reading and in most spoken MSA, people usually do not pronounce all case endings clearly.

So you will often hear something like:

هل تستطيعين أن تكتبي رقم هاتفك على هذه الصفحة؟

without fully pronouncing endings such as:

• رقمَ
• الصفحةِ

This is completely normal. The grammar is still there, even when the short endings are left unspoken.