هو زميل جديد.

• هو = he
• زميل = colleague, classmate, or fellow student/coworker, depending on context
• جديد = new

So the sentence is made of a pronoun plus a noun phrase: he + new colleague.

In Arabic, the verb to be is usually not written or spoken in the present tense in sentences like this.

So:

• هو زميل جديد = He is a new colleague

But in the past or future, Arabic does use verbs such as كان for was:

• كان زميلًا جديدًا = He was a new colleague

This is very normal in Arabic and is one of the first big differences English speakers notice.

Yes, if you want to clearly say He is ..., you need هو as the subject.

If you say only:

• زميل جديد

that usually means just a new colleague as a noun phrase, not a complete sentence with he.

So هو is what gives you the meaning he is.

This is a nominal sentence in Arabic, called جملة اسمية.

It does not begin with a verb. Instead, it begins with a pronoun or noun:

• هو = the topic/subject
• زميل جديد = the predicate/comment about him

So the structure is basically:

• subject + predicate

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

So:

• زميل جديد = a new colleague

This is the normal order in Arabic:

• noun first
• adjective second

Unlike English, Arabic does not usually put the adjective before the noun.

Because زميل is masculine singular, so the adjective must also be masculine singular.

Arabic adjectives agree with the noun in:

• gender
• number
• definiteness
• case

So:

• زميل جديد = masculine singular
• زميلة جديدة = feminine singular

If you wanted She is a new colleague, you would say:

• هي زميلة جديدة

Because the phrase is indefinite: a new colleague, not the new colleague.

So:

• زميل جديد = a new colleague

If you want the new colleague, both the noun and adjective become definite:

• الزميل الجديد

This is important: in Arabic, if the noun is definite, the adjective must also be definite.

You would say:

هو الزميل الجديد

Notice that both words in the noun phrase take الـ:

• الزميل = the colleague
• الجديد = the new

That is because Arabic adjectives match the noun in definiteness.

In fully vocalized MSA, it is:

هُوَ زَمِيلٌ جَدِيدٌ

Both زميلٌ and جديدٌ are in the nominative here.

However, in normal everyday writing, these short vowel endings are usually not written, so you normally just see:

هو زميل جديد

And when people pause at the end of the sentence, they often do not pronounce the final case endings clearly.

A careful MSA pronunciation is:

huwa zamīlun jadīdun

If said in pause, you will often hear something closer to:

huwa zamīl jadīd

Useful notes:

• هو is huwa
• زميل has a long ī sound: za-mīl
• جديد also has a long ī: ja-dīd

Not always. زميل can mean several related things, depending on context:

• colleague
• classmate
• fellow student
• coworker
• peer

So the exact English translation depends on the situation.

Yes, but the meaning changes.

• هو زميل جديد = He is a new colleague
• هذا زميل جديد = This is a new colleague

Use هذا when pointing to someone or introducing someone as this person.

So both are correct, but they are not the same sentence.

For feminine singular:

• هي زميلة جديدة = She is a new colleague

For masculine plural:

• هم زملاء جدد = They are new colleagues

For feminine plural:

• هن زميلات جديدات = They are new colleagues

This shows again that Arabic adjectives change to match the noun.