يستعمل صديقي المقشرة.

A simple breakdown is:

• يستعمل = he uses / uses
• صديقي = my friend
• المقشرة = the peeler or the peeling tool

So the Arabic order is literally uses my friend the peeler, but natural English is My friend uses the peeler.

Arabic often allows the verb to come first.

Because this is a very normal verb-first sentence in Arabic.

So:

• يستعمل صديقي المقشرة = My friend uses the peeler

This is a verbal sentence in traditional Arabic grammar, because it begins with a verb.

You can also say:

• صديقي يستعمل المقشرة

That is also correct, but it puts my friend first and can sound a bit more topic-focused or emphatic, depending on context.

يستعمل is a present-tense/imperfect verb meaning he uses.

A few useful points:

• the prefix يـ often marks he in the present tense
• so يستعمل = he uses
• the dictionary form is استعمل = to use

This verb comes from the root ع م ل, which is related to work/do, but in this form استعمل means to use or to employ.

Because the ending ـي is the attached pronoun meaning my.

So:

• صديق = friend
• صديقي = my friend

This is extremely common in Arabic. Compare:

• كتابي = my book
• بيتي = my house
• أخي = my brother

So صديقي is literally friend-my.

Because صديقي is already definite.

When a noun has a possessive ending like ـي meaning my, it is automatically definite. In other words, my friend is already specific, so you do not add ال.

So:

• صديق = a friend / friend
• صديقي = my friend

You do not say الصديقي for my friend.

المقشرة is a noun referring to a peeler or peeling tool.

The ending ة is the tāʾ marbūṭa, which usually marks a feminine noun in Arabic.

Important point: this does not mean the object is biologically female. It just means the noun is grammatically feminine.

Many tool nouns and everyday objects are grammatically feminine in Arabic.

Because it is definite: the peeler, not a peeler.

So:

• مقشرة = a peeler
• المقشرة = the peeler

The الـ is the Arabic definite article, equivalent to the in English.

In this sentence:

• يستعمل = the verb
• صديقي = the subject: my friend
• المقشرة = the direct object: the peeler

So the action is:

• my friend is doing the using
• the peeler is the thing being used

Even though the subject comes after the verb in Arabic, it is still the subject.

With full case endings, the sentence would be:

يَسْتَعْمِلُ صَدِيقِي الْمِقْشَرَةَ

A few things are happening here:

• يَسْتَعْمِلُ ends in ـُ because it is a normal present-tense verb here
• الْمِقْشَرَةَ ends in ـَ because it is the direct object
• صديقي is the subject, so grammatically it is nominative, but with the ـي possessive ending, the case is not clearly visible in the usual written form

In ordinary unvowelled Arabic writing, you usually just see:

يستعمل صديقي المقشرة

A helpful pronunciation is:

yastaʿmilu ṣadīqī al-miqsharah

If you pronounce full case endings in careful reading, it can be:

yastaʿmilu ṣadīqī al-miqsharata

A few notes:

• ʿ represents the Arabic letter ع
• ṣ represents the emphatic ص
• the final ة is often heard as -ah in pause, but as -at when fully inflected in connected formal reading