אני שומעת הודעה ברמקול, אבל אני לא מבינה הכול.

Because the speaker is feminine singular.

In Hebrew present tense, verbs agree with the subject in gender and number. Since the subject is אני and the speaker is female, the sentence uses:

• שומעת = hearing / hear / am hearing
• מבינה = understanding / understand / am understanding

If the speaker were male, you would say:

• אני שומע הודעה ברמקול, אבל אני לא מבין הכול.

No. אני means I for both males and females.

What shows the speaker’s gender here is the verb form:

• אני שומעת / מבינה = a female speaker
• אני שומע / מבין = a male speaker

This is very common in Hebrew: the pronoun may stay the same, but the verb changes.

Yes, you could leave it out.

The sentence could also be:

• אני שומעת הודעה ברמקול, אבל לא מבינה הכול.

That is still natural Hebrew.

Why repeat אני then? Because it can make the sentence feel:

• clearer
• more balanced
• slightly more emphatic

In present tense, Hebrew often keeps the subject pronoun because the present-tense verb does not clearly show person the way some other forms do.

It can mean both.

Hebrew present tense often covers both:

• simple present: I hear
• present progressive: I am hearing

So אני שומעת הודעה ברמקול can mean:

• I hear an announcement over the loudspeaker
• I’m hearing an announcement over the loudspeaker

The exact sense comes from context.

הודעה can mean several related things, such as:

• message
• announcement
• notification

In this sentence, because of ברמקול, it most naturally means announcement or message being broadcast over a speaker.

So although הודעה is often used for things like a text notification, here it is understood as something spoken aloud.

ברמקול is made from:

• ב־ = in / on / through / via
• רמקול = speaker / loudspeaker

So ברמקול literally means something like:

• through a loudspeaker
• over the speaker

Hebrew often attaches short prepositions directly to the following noun, so they become one written word.

In context, הודעה ברמקול means an announcement heard over the loudspeaker.

Because שומעת means hear, while מקשיבה means listen.

• לשמוע = to hear
• להקשיב = to listen

In this sentence, the idea is that the speaker is perceiving the sound of the announcement. That fits שומעת.

If you said אני מקשיבה להודעה, that would mean I am listening to the announcement, which suggests more active attention.

So:

• אני שומעת הודעה = I hear an announcement
• אני מקשיבה להודעה = I am listening to an announcement

Hebrew usually makes a present-tense sentence negative by putting לא directly before the verb.

So:

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

This is the normal everyday way to say not in Hebrew.

Because הכול means everything / all of it, while כל usually means every or all before another noun.

Compare:

• הכול = everything
• כל יום = every day
• כל האנשים = all the people

So in this sentence:

• אני לא מבינה הכול = I don’t understand everything

That means she understands some of it, but not all.

Also, you may see הכל instead of הכול. Both spellings are common; הכול is a fuller spelling.

This is an important difference:

• אני לא מבינה הכול = I don’t understand everything
  • I understand part of it, but not all of it.
• אני לא מבינה כלום = I don’t understand anything
  • I understand nothing.

So הכול is partial lack of understanding, while כלום is total lack of understanding.

Yes, it is very natural.

The structure is:

• אני = subject
• שומעת = verb
• הודעה = object
• ברמקול = prepositional phrase
• אבל = but
• אני לא מבינה הכול = second clause

So the overall flow is close to English:

• I hear an announcement over the loudspeaker, but I don’t understand everything.

Hebrew can sometimes vary word order for emphasis, but this version is standard and neutral.

The most natural English translation is over the loudspeaker or through the loudspeaker.

Even though ב־ often means in, Hebrew prepositions are broader than direct word-for-word English equivalents. In this context, ברמקול does not mean physically inside a speaker. It means the sound is coming through it.

So idiomatic English would be:

• I hear an announcement over the loudspeaker.

A simple pronunciation guide:

• אני — ah-NEE
• שומעת — sho-MA-at
• הודעה — ho-da-AH
• ברמקול — be-raam-KOL or ba-raam-KOL depending on pronunciation style
• אבל — a-VAL
• לא — loh
• מבינה — me-vee-NAH
• הכול — ha-KOL

A useful thing to notice is that שומעת and הודעה both have a slight break between vowels because of the guttural letter involved, so they are not usually smoothed into one syllable.