בחדר העבודה יש מחשב, מקלדת ועכבר.

יש is the Hebrew word used for there is or there are.

Hebrew usually does not use a present-tense verb meaning is/are in this kind of sentence. Instead, it uses יש to say that something exists or is present.

• יש מחשב = there is a computer
• יש מחשבים = there are computers

Notice that יש stays the same in both singular and plural.

Hebrew often puts the location first to set the scene.

So בחדר העבודה יש מחשב... is a very natural way to say In the study/office, there is a computer...

You could also say:

• יש בחדר העבודה מחשב, מקלדת ועכבר.

That is also correct. Starting with בחדר העבודה gives a little more focus to the place.

Because this is a construct chain (smikhut), a very common Hebrew structure meaning something like X of Y.

• חדר עבודה = a work room / study
• חדר העבודה = the work room / the study

In this structure, the first noun normally does not take ה־. The definiteness is marked on the second noun, and that makes the whole phrase definite.

So:

• חדר העבודה literally = room of the work
• natural English = the study, the office, or the work room, depending on context

It is usually understood as in the study / in the office.

A natural pronunciation is:

be-cheder ha-avodá

This is important because in unpointed Hebrew, בחדר can look ambiguous. In a simple phrase, בחדר could mean in the room and be pronounced ba-cheder. But here, because חדר העבודה is a construct chain, the first noun חדר does not take ה־, so the phrase is read as be-cheder ha-avodá.

Because they are indefinite here:

• מחשב = a computer
• מקלדת = a keyboard
• עכבר = a mouse

After יש, Hebrew very often uses indefinite nouns, because you are introducing things that are present or available.

So the sentence is presenting these items as a computer, a keyboard, and a mouse, not the computer, the keyboard, and the mouse.

That is the normal modern Hebrew way to write a list, just like in English:

• computer, keyboard, and mouse

So:

• מחשב, מקלדת ועכבר

Hebrew uses commas between items, and the last item usually gets ו־ meaning and.

No. יש does not change.

It works with:

• masculine singular: יש מחשב
• feminine singular: יש מקלדת
• plural: יש מחשבים

So even though מחשב is masculine and מקלדת is feminine, יש remains exactly the same.

Because את is used before definite direct objects, and that is not what is happening here.

In this sentence, יש is an existential construction: it means there is / there are. The nouns after it are simply the things that exist in that place. They are also indefinite, which is another reason את would not appear.

So:

• יש מחשב is correct
• יש את המחשב would be a very different structure and not the normal meaning here

Yes. עכבר can mean both mouse the animal and computer mouse.

Context tells you which meaning is intended. Since this sentence also mentions computer and keyboard, עכבר clearly means a computer mouse here.

A natural pronunciation is:

be-cheder ha-avodá yesh makhshev, miklédet ve-akhbár.

A few helpful notes:

• יש = yesh
• מחשב = makhshev
• מקלדת = miklédet
• עכבר = akhbár
• עבודה = avodá

The stress is typically near the end in avodá, miklédet, and akhbár.