Η φίλη μου είναι διστακτική με τους αγνώστους, αλλά όταν τους γνωρίσει καλύτερα τους χαιρετάει πάντα με χαμόγελο.

It can mean either, depending on context.

• η φίλη μου literally means my female friend
• In some contexts, it can also mean my girlfriend

If the broader situation is romantic, a Greek speaker may understand girlfriend. If not, it is usually just my friend. In this sentence, without any romantic context, most learners should understand it as my female friend.

In Greek, unstressed possessives like μου often come after the noun:

• η φίλη μου = my friend
• το βιβλίο μου = my book

This is the normal pattern in everyday Greek. English puts my before the noun, but Greek usually puts μου, σου, του, etc. after it.

Because φίλη is a feminine noun, and the adjective must agree with it.

So:

• η φίλη = feminine singular
• διστακτική = feminine singular

Greek adjectives change form to match the noun in gender, number, and case.

Compare:

• ο φίλος είναι διστακτικός = the male friend is hesitant/reserved
• η φίλη είναι διστακτική = the female friend is hesitant/reserved

Here διστακτική means something like:

• hesitant
• reserved
• shy
• timid, depending on context

In this sentence, it suggests that she is not immediately warm or open with strangers. So reserved around strangers is a very natural way to understand it.

Greek often uses the definite article in places where English does not.

So:

• με τους αγνώστους literally looks like with the strangers
• but in natural English here it means with strangers or around strangers

This is very common in Greek. The article is often used with general groups or categories of people.

Also, με takes the accusative, which is why you get:

• τους αγνώστους = masculine accusative plural

Originally, άγνωστος is an adjective meaning unknown.

But here it is being used as a noun:

• οι άγνωστοι = strangers
• τους αγνώστους = strangers, in the accusative plural

This is very common in Greek: an adjective can function like a noun when the meaning is clear.

No, γνωρίσει here is not a past tense.

In this sentence, γνωρίσει is the form used after όταν to express a future or general completed action:

• όταν τους γνωρίσει καλύτερα = when she gets to know them better

A helpful way to think about it is:

• γνωρίζει = she knows / she is knowing / she gets to know in an ongoing sense
• γνωρίσει = she comes to know / gets to know, as a completed step

So the sentence means that after she becomes more familiar with them, her behavior changes.

That τους means them.

So:

• τους γνωρίσει = gets to know them

It is the direct object pronoun, and in Greek these short object pronouns usually come before the verb.

Compare:

• βλέπω τους φίλους = I see the friends
• τους βλέπω = I see them

The same thing happens here:

• τους γνωρίσει = know them / get to know them

Because them is also the object of the second verb.

So the sentence contains two actions with the same people as the object:

• she gets to know them
• she greets them

That is why τους appears twice:

• όταν τους γνωρίσει καλύτερα
• τους χαιρετάει πάντα

In English, we also repeat them if we say the whole thing fully: when she gets to know them better, she always greets them with a smile.

καλύτερα means better, and here it is an adverb.

It modifies the verb γνωρίσει:

• γνωρίσει καλύτερα = get to know better

It is not describing a noun; it is describing how well she gets to know them.

Compare:

• adjective: καλός φίλος = a good friend
• adverb: μιλάει καλά = she speaks well
• comparative adverb: μιλάει καλύτερα = she speaks better

Because Greek often leaves out subject pronouns when the verb ending already shows who the subject is.

Here:

• είναι = is
• γνωρίσει = she gets to know
• χαιρετάει = she greets

The subject is understood from the context as η φίλη μου.

Greek does have the pronoun αυτή for she, but it is usually only used for emphasis, contrast, or clarity. In a sentence like this, it would sound unnecessary.

Yes. Both are possible in Modern Greek.

• χαιρετάει
• χαιρετά

Both mean she greets.

The -άει form is very common in everyday speech and writing, while the shorter form is also standard. You will often see both kinds of present-tense forms with verbs like this.

So:

• τους χαιρετάει πάντα
• τους χαιρετά πάντα

Both are correct.

με χαμόγελο literally means with a smile, and it expresses manner: how she greets them.

So:

• τους χαιρετάει πάντα με χαμόγελο = she always greets them with a smile

Greek could also use other expressions, including ones built around smiling, but με χαμόγελο is a very natural and simple way to say it.

Also notice that there is no article here:

• με χαμόγελο = with a smile / smilingly, in a general way

Greek often omits the article in short manner expressions like this. You could also hear με ένα χαμόγελο, which would sound a bit more like with a smile in a more concrete sense.

It breaks down like this:

• Η φίλη μου = my friend
• είναι διστακτική με τους αγνώστους = is reserved with strangers
• αλλά = but
• όταν τους γνωρίσει καλύτερα = when she gets to know them better
• τους χαιρετάει πάντα με χαμόγελο = she always greets them with a smile

So the pattern is:

main clause + αλλά + time clause + main clause

This is a very common Greek structure, and the object pronouns τους come before the verbs they belong to.