את יכולה להביא עוד סכין מהמטבח?

Because Hebrew writes both words the same way in unpointed text.

Here, את means you addressed to one female, and it is pronounced at.
The direct-object marker את is pronounced et and appears before a definite direct object, which is not what is happening here.

In this sentence, את is the subject: you can bring...

Because it uses the feminine singular forms:

• את = you (to one female)
• יכולה = can / able to in the feminine singular

If you were speaking to one male, it would be:

אתה יכול להביא עוד סכין מהמטבח?

יכולה agrees with the person being addressed.

Hebrew often marks gender in the second person, so when speaking to one woman, you use feminine forms:

• את יכולה

With one man:

• אתה יכול

With several women:

• אתן יכולות

With several men or a mixed group:

• אתם יכולים

Grammatically, it is about ability: Are you able to bring...?

But in real usage, it commonly functions as a polite request, just like English Can you bring...? or sometimes Could you bring...?

So it is softer and more natural than giving a direct command.

After יכול / יכולה in Hebrew, the next verb is normally in the infinitive.

So:

• יכולה להביא = can bring / be able to bring

Here, להביא means to bring.
The ל־ is the usual infinitive marker, similar to English to.

Yes. A direct command to one woman would be:

הביאי עוד סכין מהמטבח.

That is grammatical, but it is more direct.
את יכולה להביא... ? sounds less blunt and is a very natural way to ask someone to do something.

Sometimes yes, but in the present tense, Hebrew often keeps the subject pronoun because the verb form does not clearly show person.

For example, יכולה can mean:

• you (feminine singular) are able
• she is able

So את helps make it clear that the speaker means you.

Here, עוד means another, one more, or additional.

So:

• עוד סכין = another knife / one more knife

In other contexts, עוד can also mean still or yet, so learners often need to determine its meaning from context.

Because סכין here is indefinite: a knife / another knife, not the knife.

In Hebrew, the direct-object marker את is used only before definite direct objects.

So:

• להביא עוד סכין = to bring another knife
• להביא את הסכין = to bring the knife

סכין is feminine.

That is not especially obvious from its form, so it is the kind of noun whose gender usually just has to be learned.

For example:

• סכין חדה = a sharp knife

מהמטבח means from the kitchen.

It is made of:

• מ־ = from
• המטבח = the kitchen

So the whole word literally means from the kitchen.

In everyday Hebrew, yes/no questions usually do not need a special question word.

The sentence can look just like a statement, and the question is shown by:

• intonation in speech
• a question mark in writing

So את יכולה להביא עוד סכין מהמטבח? is a very normal spoken-style question.
Adding האם would sound more formal.

The sentence is:

• את = subject
• יכולה = modal idea, can / able to
• להביא = infinitive, to bring
• עוד סכין = object, another knife
• מהמטבח = prepositional phrase, from the kitchen

So the structure is roughly:

subject + can + infinitive + object + prepositional phrase

That word order is very natural in Hebrew.

A common approximate pronunciation is:

at yekhoLA lehaVI od saKIN meha-mitBÁKH?

A few useful notes:

• את here is at
• סכין is stressed on the second syllable: saKIN
• ח in מטבח is a throaty sound, often approximated by English speakers with the ch in Bach