Nilipoazima kitabu, mkutubi alinipa kalamu ili niweke saini kwenye rejesta.

Nilipoazima can be broken into:

• ni- = I
• -li- = past tense
• -po- = when
• azim- = verb root borrow
• -a = final vowel

So nilipoazima kitabu means when I borrowed the book.

For many learners, the important part is -po-, because it often gives the sense of when in sentences like this.

In this sentence, kuazima means to borrow.

So:

• kuazima kitabu = to borrow a book

This can be confusing because English clearly separates borrow and lend, while Swahili learners often meet several related forms. A useful contrast is:

• kuazima = to borrow
• kuazimisha = to lend

So here, the speaker is the one borrowing the book.

Because in Swahili, object pronouns are usually built into the verb.

Alinipa breaks down as:

• a- = he/she
• -li- = past tense
• -ni- = me
• -pa = give

So alinipa literally means he/she gave me.

English uses separate words: gave me.
Swahili often packs that information into a single verb.

It can mean either he gave me or she gave me.

Swahili does not normally mark gender in this kind of verb agreement.
So a- can refer to:

• he
• she

You only know which one is meant from context.

Mkutubi means librarian.

It is a noun referring to a person, so it belongs to the m-/wa- class pair (noun class 1/2), which is very common for singular/plural people:

• singular: mkutubi
• plural: wakutubi

Because it is singular and refers to a person, the verb uses the subject marker a-:

• mkutubi alinipa = the librarian gave me

If it were plural, you would expect wa- instead:

• wakutubi walinipa = the librarians gave me

Ili means so that or in order that.

After ili, Swahili usually uses the subjunctive, not the ordinary past tense. That is why you get:

• niweke = that I put / so that I may put

Breaking it down:

• ni- = I
• wek- = verb root put
• -e = subjunctive ending

So:

• ili niweke saini = so that I could sign / in order for me to sign

A form like ili niliweka would not fit this purpose meaning.

Here, Swahili is using a very common expression:

• weka saini = literally put a signature
• natural meaning: sign

So ili niweke saini means so that I could sign.

This may sound more literal than English, but it is a normal way to express the idea. You may also hear forms based on kusaini in modern usage, but weka saini is perfectly natural and very transparent for learners.

Kwenye rejesta means in the register or on the register, depending on how you think about it in English.

• kwenye is a very common locative word meaning something like in / on / at
• rejesta = register, a loanword

With documents, books, lists, and surfaces, English sometimes chooses in and sometimes on, but Swahili kwenye works well in many of these situations.

So:

• kwenye rejesta = in the register / on the register

Yes, it is fairly similar.

The sentence is:

• Nilipoazima kitabu, mkutubi alinipa kalamu ili niweke saini kwenye rejesta.

A natural structure in English is:

• When I borrowed the book, the librarian gave me a pen so that I could sign the register.

So the order is broadly:

1. When I borrowed the book
2. the librarian gave me a pen
3. so that I could sign in/on the register

That makes this a good sentence for learners, because although some grammar inside the verbs is different, the overall flow is quite familiar.

It could, but Swahili often prefers a straightforward active structure here:

• mkutubi alinipa kalamu = the librarian gave me a pen

This is usually simpler and more natural than trying to make it passive.

Swahili certainly can form passives, but in an everyday sentence like this, the active version is very normal and direct.

Not exactly. Nilipoazima most directly means when I borrowed.

Depending on context, English might sometimes translate it more loosely as after I borrowed, but the core idea of -po- here is when. If you want learners to understand the grammar accurately, when I borrowed is the best starting point.