هو ينسحب من الدورة المسائية.

In Arabic, the verb ينسحب already shows third person masculine singular, so the subject pronoun is often understood.

So all of these are possible:

• ينسحب من الدورة المسائية = He is withdrawing from the evening course
• هو ينسحب من الدورة المسائية = same basic meaning, but هو can add clarity or slight emphasis

In many real Arabic sentences, the pronoun would simply be omitted unless the speaker wants to highlight the subject or make it extra clear.

ينسحب is in the imperfect form. In Modern Standard Arabic, the imperfect can express several related meanings depending on context, including:

• he withdraws
• he is withdrawing
• he does withdraw

So this sentence could mean either a general present or an action happening now, depending on context.

If you want a clear future meaning, Arabic often uses:

• سينسحب = he will withdraw
• سوف ينسحب = he will withdraw

The dictionary form is انسحب.

That is the past tense / citation form, and it means to withdraw, to pull out, or to back out depending on context.

From that verb, you get:

• انسحب = he withdrew
• ينسحب = he withdraws / is withdrawing

So ينسحب is just the present/imperfect form of انسحب.

Because Arabic uses انسحب من ... to mean withdraw from ...

So:

• ينسحب من الدورة = he withdraws from the course

This works very much like English withdraw from.
The preposition من marks the thing he is leaving, quitting, or pulling out of.

Here, الدورة means course.

But this word has a wider range of meanings in Arabic depending on context, such as:

• course
• training course
• cycle
• round
• session

So learners should know that دورة is a flexible word. In this sentence, because of the context, it means course.

Because in Arabic, adjectives normally come after the noun they describe.

So:

• الدورة = the course
• المسائية = evening
• الدورة المسائية = the evening course

This is the normal Arabic order:

• noun first
• adjective second

That is the opposite of English, where we usually put the adjective first.

Because المسائية is describing الدورة, and الدورة is a feminine noun.

Arabic adjectives must agree with the noun they describe in:

• gender
• number
• definiteness
• case

So:

• masculine: مسائي
• feminine: مسائية

Since دورة is feminine, the adjective must also be feminine:

• الدورة المسائية

Because Arabic adjectives must also match the noun in definiteness.

So if the noun is definite, the adjective must be definite too.

• دورة مسائية = an evening course
• الدورة المسائية = the evening course

That is why both words take ال here.

After the preposition من, the noun is in the genitive case.

So in fully vocalized Arabic, you would have:

• منَ الدَّورَةِ المسائيَّةِ

Both the noun and its adjective take the genitive ending because:

1. الدورة comes after a preposition
2. المسائية must match الدورة

In everyday reading and speech, these final case vowels are often not pronounced clearly, but in formal grammar they are important.

Although it is written الدورة, it is pronounced ad-dawra rather than al-dawra.

That is because د is a sun letter. With sun letters, the ل in ال is not pronounced, and the next consonant is doubled.

So:

• الدورة → ad-dawra
• المسائية → al-masāʾiyya

Notice the difference:

• د is a sun letter, so assimilation happens
• م is a moon letter, so ال stays pronounced normally

Yes. That is very normal in Arabic.

The imperfect form ينسحب does not force a single English tense. Depending on context, it can mean:

• he withdraws
• he is withdrawing

English makes a stronger distinction between simple present and present progressive. Arabic often leaves that difference to context.

Both are natural, but they feel slightly different.

• ينسحب من الدورة المسائية is often more neutral and economical
• هو ينسحب من الدورة المسائية makes the subject more explicit

Adding هو may be useful when:

• you are contrasting him with someone else
• you want extra emphasis
• you want to avoid ambiguity

So the version with هو is correct, but the shorter version is also very common.