אני לא מבינה מה שאת אומרת.

Because אני does not show gender in Hebrew. It can mean I for both men and women.

The gender shows up in the verb form used in the present tense:

• מבין = masculine singular
• מבינה = feminine singular

So אני לא מבינה means the speaker is female.

A male speaker would say:

• אני לא מבין מה שאת אומרת.

Because אומרת agrees with את, which here means you addressed to one female.

In Hebrew present tense, the verb agrees with the subject in gender and number:

• את אומרת = you (feminine singular) say / are saying
• אתה אומר = you (masculine singular) say / are saying

So this sentence is being said to a woman or girl.

לא is the standard word for not.

In simple present-tense sentences, Hebrew usually places לא before the verb or predicate:

• אני לא מבינה = I do not understand
• הוא לא בא = he is not coming / he does not come

So לא works very much like English not, but its position is fixed more directly before what it negates.

שאת is made of two parts:

• ש־ = that
• את = you (feminine singular)

So:

• שאת אומרת = that you are saying

In this sentence, it helps build the clause what you are saying.

A very common beginner confusion is that שאת looks like one indivisible word, but grammatically it is:

• ש־ + את

No. Here את is the pronoun you (feminine singular), not the direct object marker.

Hebrew has two different things spelled את:

1. את = the direct object marker
2. אַתְ / את = you (feminine singular)

In this sentence, it must be the pronoun, because it is followed by a verb that agrees with it:

• את אומרת = you (f.) say

So the structure is not object marking here at all.

Great question. These two forms are related, but they do different jobs.

• מה את אומרת? = What are you saying?
  This is a direct question.

• מה שאת אומרת = what you are saying
  This is an embedded clause, not a standalone question.

In your sentence, the speaker is not asking What are you saying? Instead, they are saying they do not understand the thing that you are saying. That is why ש־ appears.

Sometimes Hebrew can drop subject pronouns, but here אני is very natural and often helpful.

One reason is that in the present tense, forms like מבינה show gender and number, but not person as clearly as English does. So אני makes the sentence explicit and clear:

• אני לא מבינה... = I do not understand...

In casual speech, if the context is obvious, someone might say:

• לא מבינה מה שאת אומרת.

But for learners, and in many normal situations, keeping אני is the safest and most natural choice.

Yes, this is Hebrew present tense.

In modern Hebrew, the present tense is usually built from forms that historically come from participles. That is why they often look different from past and future forms.

For example, from להבין = to understand:

• מבין / מבינה = understand / am understanding
• הבנתי = I understood
• אבין = I will understand

And from לומר = to say:

• אומר / אומרת = say / am saying
• אמרתי = I said
• אומר can also sometimes mean will say in certain formal/biblical-style contexts, but in modern everyday Hebrew here it is simply present tense

So in this sentence, both מבינה and אומרת are present-tense forms.

The verb forms would change according to gender.

Female speaker to female listener:

• אני לא מבינה מה שאת אומרת.

Male speaker to female listener:

• אני לא מבין מה שאת אומרת.

Female speaker to male listener:

• אני לא מבינה מה שאתה אומר.

Male speaker to male listener:

• אני לא מבין מה שאתה אומר.

So there are two separate gender choices here:

1. the speaker’s gender → מבין / מבינה
2. the listener’s gender → את אומרת / אתה אומר

A common pronunciation is:

• ani lo meviná ma she'at oméret

A few notes:

• אני = ani
• לא = lo
• מבינה = meviná
• מה = ma
• שאת = she'at or roughly sheat, with a break between the vowels
• אומרת = oméret

In natural fast speech, the middle part may sound quite smooth and connected:

• ...ma she'at oméret

This word order is the normal, neutral one:

• אני לא מבינה מה שאת אומרת.

Hebrew does allow some flexibility, but changing the order often adds emphasis or sounds less neutral.

For example, fronting parts of the sentence can sound marked or emotional. For a learner, this standard order is the best pattern to use.

So the safest takeaway is:

• subject + לא + present-tense verb + clause

In this sentence:

• אני
  • לא
    • מבינה
      • מה שאת אומרת