Stima iliporudi, baba akaangalia tena gia ya mashine ya kusagia.

Iliporudi can be analyzed as:

• i- = subject marker for the noun class of stima
• -li- = past tense
• -po- = a relative/temporal marker that often gives the sense when
• -rudi = return / come back

So iliporudi means when it returned or, more naturally here, when the power came back.

A useful comparison:

• ilirudi = it returned
• iliporudi = when it returned

So the -po- is what turns it into a when... clause.

In Swahili, verbs agree with the noun class of their subject.

Stima is usually treated like a class 9 noun, and class 9 singular commonly takes the subject marker i-.

That is why you get:

• stima ilirudi = the electricity returned
• stima iliporudi = when the electricity returned

A learner might expect something like u- or a-, but i- is correct because the agreement follows noun class, not English-style natural gender.

Akaangalia can be broken down like this:

• a- = he/she subject marker
• -ka- = consecutive / narrative marker
• -angalia = look at, inspect, check

So akaangalia means something like:

• then he looked at
• then he checked
• and he looked at

In this sentence, it connects naturally to the earlier event:

• When the electricity came back, father then checked again...

The -ka- often gives a sense of the next event in the sequence.

Because baba refers to a person, it takes the agreement pattern of class 1 in the singular.

So even though baba does not visibly begin with a class prefix like some other nouns, the verb still agrees with it as an animate singular noun:

• baba akaangalia = father then checked
• baba aliangalia = father checked

This is very common with kinship terms and other nouns referring to people.

Yes, it could, but the nuance changes.

• aliangalia = he looked / he checked in the simple past
• akaangalia = then he looked / and he checked, with a stronger sense of sequence

In your sentence, akaangalia fits well because the first clause sets up a situation:

• Stima iliporudi... = When the electricity came back...

Then the next action follows:

• baba akaangalia tena... = father then checked again...

So akaangalia makes the sentence feel more connected and narrative.

Both ya forms are connectors, often called possessive or associative linkers.

They link nouns or noun-like expressions together.

1. gia ya mashine
   = gear of the machine / the machine's gear

2. mashine ya kusagia
   = machine for grinding / grinding machine

So the whole phrase is built step by step:

• gia = gear
• gia ya mashine = gear of the machine
• gia ya mashine ya kusagia = gear of the grinding machine

The reason both are ya is that gia and mashine are both treated in a class that uses ya for this linker.

Kusagia is an infinitive form:

• ku- = to
• -sagia = grind

After a noun like mashine, an infinitive can describe the purpose or function of that noun.

So:

• mashine ya kusagia literally means machine of grinding
• more naturally: machine for grinding or grinding machine

This is a very common Swahili pattern:

• kisu cha kukatia = knife for cutting
• chumba cha kulala = room for sleeping / bedroom
• mashine ya kusagia = machine for grinding

Because that is a very natural position for adverbs like tena in Swahili.

• akaangalia tena = he checked again

Placing tena after the verb is the most neutral, ordinary order.

It tells you that the action of checking happened again. In context, this probably means father had already checked the gear before, and after the power returned, he checked it once more.

Swahili usually does not use articles the way English does.

So a sentence can simply say:

• baba
• gia
• mashine

and context tells you whether English should translate them as:

• father, the father, dad
• a gear, the gear
• a machine, the machine

That is why English translations often add the or a/an, even though no separate word is present in the Swahili sentence.

Not strictly, but it is helpful.

The comma shows that Stima iliporudi is a fronted time clause:

• When the electricity came back, ...

In Swahili writing, punctuation is sometimes used more lightly than in English, so you may see the sentence written with or without the comma. But here the comma makes the structure easier to read.