Nilipojikata kidole, mama aliweka plasta.

It is made of several pieces:

• ni- = I
• -li- = past tense
• -po- = when / at the time when
• ji- = reflexive, meaning myself
• kata = cut

So nilipojikata means something like when I cut myself.

This is a very common Swahili pattern: a lot of grammatical information is packed into one verb.

Here, -po- marks a time relationship, so it gives the idea of when.

So:

• nilikata = I cut
• nilipokata = when I cut

In this sentence, nilipojikata kidole means when I cut my finger.

You can think of -po- here as turning the verb into a when-clause.

ji- is the reflexive marker, meaning the action happens to the subject themself.

So:

• kukata = to cut
• kujikata = to cut oneself

In English, we usually say I cut my finger, not I cut myself finger. But in Swahili, with body parts, it is very natural to use the reflexive plus the body part:

• nilipojikata kidole = when I cut my finger

Without ji-, the sentence would be less clearly about hurting your own body.

Because in Swahili, body parts often do not need a possessive if the owner is already obvious.

So nilipojikata kidole naturally means when I cut my finger, even though my is not stated.

You can say kidole changu if you want to be extra explicit or emphatic, but it is often unnecessary.

This is similar to how some languages treat body parts more naturally than English does.

Kidole means finger, and it belongs to the ki-/vi- noun class.

• singular: kidole = finger
• plural: vidole = fingers

So the noun class changes like this:

• ki- in the singular
• vi- in the plural

This is a very common Swahili noun class pattern.

It breaks down like this:

• a- = he/she
• -li- = past tense
• weka = put, place

So aliweka means he/she put.

In this sentence, because the subject is mama, it means mother/mum put.

Because Swahili often uses weka in a broad way for put, place, or apply, and the exact English wording comes from context.

So aliweka plasta is understood as she put on / applied a plaster.

If you want to state the location more explicitly, you could add something like:

• kwenye kidole = on the finger

So a fuller version could be:

• Mama aliweka plasta kwenye kidole.

But in everyday speech, the shorter version is often enough.

Mama can mean mother, mum, or sometimes just woman/lady, depending on context.

In this sentence, it most naturally means mum/mother.

Also, Swahili does not have articles like a or the, so you do not need a separate word for them.

And just like with kidole, Swahili often leaves out possessives when the meaning is obvious from context. If needed, you could say:

• mama yangu = my mother

But mama by itself is very normal.

Yes. Plasta is a common borrowed word, from English plaster.

In East African Swahili, it usually means an adhesive plaster, like a Band-Aid.

So this is a normal everyday word in context. Borrowed words are very common in Swahili, especially for modern objects.

Yes. A few alternatives are possible, depending on what you want to emphasize.

For example:

• Nilipokata kidole changu, mama aliweka plasta.
  More explicitly says my finger.

• Baada ya kujikata kidole, mama aliweka plasta.
  This means After cutting my finger, mum put on a plaster.

• Mama aliniwekea plasta nilipojikata kidole.
  This adds the idea that she put the plaster for me / on me.

The original sentence is already natural, but Swahili often gives you more than one good way to express the same basic idea.