הם מכירים זה את זה מהאוניברסיטה.

הם means they for a masculine group or a mixed-gender group.

So this sentence is talking about:

• two or more males, or
• a group that includes at least one male

If the group were all female, standard Hebrew would use הן and change the verb too:

• הן מכירות זו את זו מהאוניברסיטה.

Also, in everyday spoken Hebrew, הם is often used very broadly, even when the group is not strictly masculine.

מכירים is the present-tense plural masculine form of להכיר.

Here, להכיר means:

• to know a person
• to be acquainted with
• to be familiar with

So הם מכירים means they know / they are acquainted with.

A useful thing to notice is that Hebrew present-tense forms often look a bit like adjectives, because they change for gender and number:

• מכיר — masculine singular
• מכירה — feminine singular
• מכירים — masculine plural
• מכירות — feminine plural

Because Hebrew uses two different verbs where English often just uses know.

• להכיר = to know a person / be acquainted with / be familiar with
• לדעת = to know a fact / know information / know how

So:

• אני מכיר אותו = I know him
• אני יודע את התשובה = I know the answer

When talking about knowing each other, Hebrew uses להכיר, not לדעת.

זה את זה means each other or one another.

It is a common Hebrew reciprocal expression. In this sentence:

• הם מכירים זה את זה = they know each other

Literally, it does not map neatly into natural English word-for-word, so it is best learned as a set phrase meaning each other.

For masculine or mixed groups, זה את זה is the standard form.
For an all-female group, standard Hebrew would use זו את זו.

את is the Hebrew direct object marker. It often appears before a definite direct object.

In the fixed expression זה את זה, the את is just part of the normal structure of the reciprocal phrase.

So even though English simply says each other, Hebrew says:

• זה את זה

You do not translate את separately here. It is part of how Hebrew builds the expression.

Yes. אחד את השני is very common in everyday Hebrew and also means each other.

So you may hear:

• הם מכירים זה את זה
• הם מכירים אחד את השני

Both are natural. Very roughly:

• זה את זה can sound a bit more standard or formal
• אחד את השני is extremely common in speech

As a learner, it is good to recognize both.

מהאוניברסיטה means from the university.

It is made of:

• מ־ / מן = from
• ה־ = the
• אוניברסיטה = university

So:

• מן + האוניברסיטה → מהאוניברסיטה

In smooth English, this usually means something like:

• from university
• from the university
• through university
• from their university days

depending on context.

Because in Hebrew, short prepositions and the definite article often attach directly to the noun.

Here:

• מ־ attaches to the word
• ה־ also stays attached

So instead of writing separate words, Hebrew writes:

• מהאוניברסיטה

This is very normal in Hebrew. You will see the same thing with other prepositions too, for example:

• באוניברסיטה = in the university
• לאוניברסיטה = to the university
• מהאוניברסיטה = from the university

Not necessarily.

It means that their connection comes from the university. In other words, the university is the source or background of how they know one another.

It could mean:

• they studied together there
• they were introduced there
• they know each other from that period of life

So the idea is broader than just they met at the university, although that may be true.

Sometimes yes.

Hebrew often allows subject pronouns to be omitted when the meaning is clear from context. Since מכירים already shows plural masculine, a speaker might say simply:

• מכירים זה את זה מהאוניברסיטה

if it is already obvious who they are.

But in an isolated sentence, keeping הם is clearer and more natural for learners.

The basic, neutral word order here is:

• הם — subject
• מכירים — verb
• זה את זה — reciprocal object
• מהאוניברסיטה — source phrase

So the sentence is built in a very normal way.

Hebrew word order can be flexible for emphasis, but for a learner, the original order is the safest pattern to use:

• הם מכירים זה את זה מהאוניברסיטה.

In standard Hebrew, you would change both the subject pronoun and the verb, and usually also the reciprocal phrase:

• הן מכירות זו את זו מהאוניברסיטה.

Changes:

• הם → הן
• מכירים → מכירות
• זה את זה → זו את זו

That said, in casual spoken Hebrew, people do not always keep these distinctions perfectly, especially in fast everyday speech. But the form above is the standard grammatical version.