אני חושבת עליהן לפעמים, כי אני כבר לא לומדת איתן.

Because the speaker is female.

In Hebrew present tense, verbs agree with the subject in gender and number:

• אני חושב = I think (said by a male)
• אני חושבת = I think (said by a female)

So אני חושבת tells you that the speaker is a woman or girl.

For the same reason: the speaker is female.

• אני לומד = I study / am studying (male speaker)
• אני לומדת = I study / am studying (female speaker)

Hebrew present-tense verbs usually show gender, even with אני.

עליהן means about them or on them, depending on context. In this sentence it means about them.

It is built from:

• על = on / about
• הן = they / them for a feminine plural group

So:

• עליהן = about them (feminine plural)

This tells you that the speaker is thinking about a group of females.

Compare:

• עליהם = about them (masculine or mixed group)
• עליהן = about them (feminine group)

Good question. Here איתן means with them, and it comes from a different use of את.

Hebrew has a set of forms meaning with me, with you, with him, with them, etc.:

• איתי = with me
• איתך = with you
• איתו = with him
• איתה = with her
• איתנו = with us
• איתם = with them (masculine/mixed)
• איתן = with them (feminine)

So in this sentence:

• אני כבר לא לומדת איתן = I no longer study with them

This איתן is not the direct object marker את. It is the prepositional form meaning with them.

Because both words refer to the same group, and that group is female.

Hebrew often marks pronouns for gender:

• them (masculine/mixed) = הם / אותם / עליהם / איתם
• them (feminine) = הן / אותן / עליהן / איתן

So this sentence strongly suggests that the speaker is talking about a group of women or girls, probably classmates.

לפעמים means sometimes.

It is a very common adverb and does not change form.

Examples:

• אני חושבת עליהן לפעמים = I think about them sometimes
• לפעמים אני עייפה = Sometimes I’m tired

In this sentence, it tells you that the action happens occasionally, not all the time.

כבר לא means no longer or not anymore.

It is a very common Hebrew pattern:

• אני כבר לא גרה שם = I no longer live there
• הוא כבר לא עובד פה = He doesn’t work here anymore

So:

• אני כבר לא לומדת איתן = I no longer study with them

Here כבר adds the idea that this used to be true before, but now it is not.

Yes, Hebrew can sometimes leave pronouns out, especially when the verb already makes the subject clear. But repeating אני is perfectly natural.

The sentence says:

• אני חושבת עליהן לפעמים, כי אני כבר לא לומדת איתן.

The second אני helps make the clause clear and balanced:

• because I no longer study with them

You could also hear:

• אני חושבת עליהן לפעמים, כי כבר לא לומדת איתן

in informal speech, but the full version with אני is clearer and more standard.

It can mean either, because Hebrew present tense often covers both the simple present and the present progressive.

So אני לומדת can mean:

• I study
• I am studying

In this sentence, the best English translation is usually:

• I no longer study with them

because it sounds more natural in English.

Because איתן already includes the meaning with them.

Hebrew often combines a preposition with a pronoun into one word:

• בי = in me
• עליו = on him / about him
• איתה = with her
• איתן = with them (feminine)

So לומדת איתן already fully means study with them.

Yes, the word order is natural, and לפעמים is fairly flexible.

The sentence has:

• אני חושבת עליהן לפעמים = I think about them sometimes

You could also say:

• לפעמים אני חושבת עליהן
• אני לפעמים חושבת עליהן

All of these can be correct, though they may sound slightly different in emphasis.

The version in your sentence is very natural and neutral.

כי means because here.

It connects the two parts of the sentence:

• אני חושבת עליהן לפעמים = I think about them sometimes
• כי אני כבר לא לומדת איתן = because I no longer study with them

So the second clause gives the reason.

Be aware that כי can also mean that in other contexts, depending on the sentence.

Yes, but some forms would change.

A male speaker would say:

• אני חושב עליהן לפעמים, כי אני כבר לא לומד איתן.

Changes:

• חושבת → חושב
• לומדת → לומד

But עליהן and איתן would stay the same if the group being referred to is still feminine plural.

Because Hebrew distinguishes between masculine/mixed plural and feminine plural in pronouns.

Here you have:

• עליהן
• איתן

Both are specifically feminine plural.

If the group were masculine or mixed, you would normally expect:

• עליהם
• איתם

So the sentence is not neutral about the group’s gender; it specifically points to a group of females.