המקדחה שלה חדשה, אבל היא לא אוהבת להשתמש במקדחה כשאין עוד מישהו בבית.

Hebrew usually expresses this kind of possession as:

noun + של + pronoun

So:

• המקדחה שלה = her drill
• literally, something like the drill of hers

This is much more natural in Modern Hebrew than trying to put a possessive word before the noun the way English does. Putting שלה before the noun would sound very unusual here.

The ה־ is the definite article, meaning the.

So:

• המקדחה שלה = her drill / the drill that belongs to her
• מקדחה שלה often means a drill of hers

In other words, the article helps mark the noun as a specific, known one. In Hebrew, a של possessive construction can still take the definite article on the noun.

Because מקדחה is a feminine noun, and adjectives in Hebrew must agree with the noun in gender and number.

So:

• מקדחה חדשה = a new drill
• המקדחה שלה חדשה = her drill is new

Compare:

• masculine singular: חדש
• feminine singular: חדשה
• masculine plural: חדשים
• feminine plural: חדשות

Grammatically, it could be either, because Hebrew has no separate neuter pronoun. A feminine noun can be referred to with היא.

So both of these are possible in principle:

• היא = she
• היא = it for a feminine noun

Here, context tells you it means she, because not liking to use a drill when no one else is home is clearly about a person. But if you were referring back to מקדחה, you would also use היא, since מקדחה is feminine.

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

Because the subject is היא = she, the sentence uses the feminine singular form:

• היא אוהבת = she likes
• הוא אוהב = he likes

So אוהבת is the correct present-tense form for a feminine singular subject.

Yes, it is functioning as a verb here.

In Modern Hebrew, present-tense verb forms are historically participles, so they often look adjective-like and behave in some adjective-like ways, especially because they agree in gender and number. But in a sentence like this, אוהבת is simply the present-tense verb: likes.

So:

• היא אוהבת = she likes
• היא לא אוהבת = she does not like

Because להשתמש requires the preposition ב־ before the thing being used.

The pattern is:

להשתמש ב־... = to use ...

So:

• להשתמש במקדחה = to use a/the drill

This is something you simply have to learn with the verb. Many Hebrew verbs come with a fixed preposition, and it does not always match English.

It is made of two parts:

• כש־ = when
• אין = there is not / there are not

So:

• כשאין = when there isn’t / when there aren’t

Hebrew normally uses אין for non-existence or absence, not לא יש. So כשאין עוד מישהו בבית means literally something like when there isn’t another person at home.

Literally, עוד מישהו is another someone or one more person, but in natural English here it means someone else or anyone else.

So:

• אין עוד מישהו בבית = there isn’t anyone else at home

The word עוד adds the idea of else / additional / another. It shows that the speaker means no other person besides her.

In Hebrew, בבית very often means at home.

Literally it is in the house, but idiomatically it is the normal way to say at home.

So:

• אני בבית = I’m at home
• מישהו בבית = someone is at home

This is just the natural Hebrew expression, even where English prefers at rather than in.

Without vowel marks, the spelling בבית can represent different possibilities, and context tells you which one is meant.

It can correspond to:

• בבית = in a house
• בבית = in the house / at home

In normal unpointed Hebrew, they are written the same way. Here, context strongly points to at home.

In unpointed Hebrew writing, במקדחה can also be ambiguous.

It may represent:

• with a drill
• with the drill

That is because ב־ attached to a noun and ב + ה־ attached to a definite noun are written the same way without vowel marks.

So the exact nuance depends on context and on the intended translation. Since the drill was already mentioned, some readers may feel it is the drill; others may understand it more generically as a drill. Both are possible from the spelling alone.