मैं शब्दकोश उधार लेती हूँ क्योंकि यह उपयोगी है।

लेती हूँ is used when the speaker is female.

• मैं ... लेती हूँ = I (female) borrow / take
• मैं ... लेता हूँ = I (male) borrow / take

In the present habitual, Hindi verbs agree with the subject, so the ending changes depending on the speaker’s gender.

उधार लेना is a very common Hindi expression meaning to borrow.

Literally:

• उधार = on loan / borrowed
• लेना = to take

So उधार लेना = to take on loan, which in natural English is to borrow.

A useful pair to remember:

• उधार लेना = to borrow
• उधार देना = to lend

This is the normal way Hindi forms the present habitual.

Structure:

• main verb stem + habitual form + होना auxiliary

So:

• लेती = habitual feminine singular form of लेना
• हूँ = am, the first-person singular form of होना

Together, लेती हूँ means something like:

• I borrow
• I do borrow
• I borrow habitually / generally

It does not usually mean I am borrowing right now. For that, Hindi would normally use ले रही हूँ.

Yes, Hindi often drops the subject pronoun when it is already clear from context.

So both of these can work:

• मैं शब्दकोश uधार लेती हूँ क्योंकि यह उपयोगी है।
• शब्दकोश उधार लेती हूँ क्योंकि यह उपयोगी है।

Including मैं makes the sentence clearer or more explicit, especially for learners or when emphasis is wanted.

Hindi usually follows Subject–Object–Verb order, while English usually uses Subject–Verb–Object.

This sentence is:

• मैं = I
• शब्दकोश = dictionary
• उधार लेती हूँ = borrow
• क्योंकि यह उपयोगी है = because it is useful

So literally the order is closer to:

• I dictionary borrow because it useful is

That is completely normal in Hindi. The main verb usually comes near the end of the clause.

Yes, शब्दकोश is generally treated as masculine.

However, in this sentence the verb लेती हूँ is agreeing with मैं (the speaker), not with शब्दकोश.

That is because in the present habitual, the verb normally agrees with the subject.

So:

• female speaker: मैं शब्दकोश उधार लेती हूँ
• male speaker: मैं शब्दकोश उधार लेता हूँ

The gender of शब्दकोश does not control लेती/लेता here.

In Hindi, यह can mean both:

• this
• it (depending on context)

Here, यह refers back to शब्दकोश, so it works like it in English:

• क्योंकि यह उपयोगी है = because it is useful

This is very normal in Hindi. The language often uses यह or वह where English would simply say it.

In Hindi, the usual pattern is:

• noun/pronoun + adjective + है

So:

• यह उपयोगी है = it is useful

Literally:

• यह = it/this
• उपयोगी = useful
• है = is

Hindi puts है at the end of this type of sentence.

No, उपयोगी usually stays the same.

It is one of many adjectives in Hindi that are effectively invariable in normal usage.

So you can have:

• यह उपयोगी है = this/it is useful
• वह उपयोगी है = that/it is useful
• वे उपयोगी हैं = they are useful

The adjective उपयोगी does not change the way adjectives like अच्छा / अच्छी / अच्छे do.

Yes, क्योंकि means because.

It introduces the reason:

• मैं शब्दकोश उधार लेती हूँ = I borrow the dictionary
• क्योंकि यह उपयोगी है = because it is useful

So the whole sentence means:

• I borrow the dictionary because it is useful.

A related word you may also see is इसलिए = therefore / so.

For example:

• यह उपयोगी है, इसलिए मैं शब्दकोश उधार लेती हूँ।
• It is useful, so I borrow the dictionary.

It normally describes a habit, general action, or something the speaker regularly does.

• लेती हूँ = habitual / simple present

So the sentence sounds like:

• I borrow the dictionary
• I tend to borrow the dictionary
• I borrow the dictionary because it is useful

If you want to say I am borrowing the dictionary right now, Hindi would normally use the progressive:

• मैं शब्दकोश उधार ले रही हूँ।

Yes, you could say मैं एक शब्दकोश उधार लेती हूँ, but it changes the feel slightly.

• शब्दकोश without एक can sound more general, like the dictionary or a dictionary, depending on context.
• एक शब्दकोश clearly means a/one dictionary.

Hindi often leaves articles unstated, so context decides whether English should use a or the.

In this sentence, the most natural interpretation is that यह refers to शब्दकोश.

So:

• क्योंकि यह उपयोगी है = because it is useful
• it = the dictionary

If you wanted to say that the borrowing is useful, you would usually phrase it differently to avoid confusion.

Yes. In everyday speech, many Hindi speakers might say डिक्शनरी instead of शब्दकोश.

For example:

• मैं डिक्शनरी उधार लेती हूँ क्योंकि यह उपयोगी है।

Both are understandable, but:

• शब्दकोश is more formal or standard Hindi
• डिक्शनरी is common in casual speech

Yes, it is grammatical and understandable.

A native speaker might also say similar natural variants such as:

• मैं शब्दकोश उधार लेती हूँ, क्योंकि यह उपयोगी है।
• मैं यह शब्दकोश उधार लेती हूँ क्योंकि यह उपयोगी है।
• मैं शब्दकोश उधार लेती हूँ क्योंकि वह बहुत उपयोगी है।

Your original sentence is perfectly fine for learning and clearly shows useful grammar:

• first-person pronoun
• habitual present
• उधार लेना
• क्योंकि
• यह ... है structure