Rahma hupiga simu kwa bibi yake mara kwa mara.

In this sentence, kupiga simu is an idiomatic expression meaning to make a phone call / to call.

Literally, piga often means hit, strike, or beat, but in Swahili it is also used in several fixed expressions where the literal meaning is not the main idea anymore. So:

• kupiga = to hit / strike
• simu = phone / telephone
• kupiga simu = to call, to make a phone call

So you should learn kupiga simu as a whole expression.

hu- marks a habitual action. It shows that something happens usually, regularly, or as a habit.

So hupiga means something like:

• usually calls
• calls regularly
• tends to call

That is why this sentence describes something Rahma does repeatedly, not just one call happening right now.

With the habitual form hu-, Swahili often uses hu- + verb stem when the subject is already clear from context or is named separately, as in Rahma hupiga.

So instead of a form built like a-na-piga or a-li-piga, the habitual pattern here is simply:

• Rahma hupiga

This is normal. The name Rahma already tells you who the subject is.

Simu is a noun meaning phone or telephone.

In Swahili, the idea to phone someone is often expressed with a noun phrase rather than a single verb. So the structure is:

• piga simu = make a phone call

That is different from English, where phone can be a noun and a verb.

Here kwa marks the person the phone call is directed to, so it works a bit like to in English.

So:

• kupiga simu kwa bibi yake = to call her grandmother

A native English speaker may expect the person to come directly after the verb, but Swahili often uses kwa in this kind of structure.

A very common alternative is to use the applied verb form:

• Rahma humpigia bibi yake simu

That also means Rahma regularly calls her grandmother.

In this sentence, bibi means grandmother.

Depending on context, bibi can also refer to an older lady, and in some situations it may have other meanings, but here the intended meaning is grandmother.

So:

• bibi yake = his/her grandmother

Yake means his, her, or its, depending on context. Swahili does not usually distinguish his and her in this form.

So:

• bibi yake can mean his grandmother or her grandmother

In your sentence, from the meaning already given, you know it refers to Rahma’s grandmother.

Also, notice that the possessive form is attached to the noun being possessed:

• bibi yake = her grandmother

This is because bibi belongs to a noun pattern that takes the possessive form yake.

Some Swahili nouns referring to people do not use the possessive pattern English speakers might expect from their meaning alone. So even though bibi refers to a person, the correct form here is:

• bibi yake

not:

• bibi wake

This is something learners often just have to get used to noun by noun.

Mara kwa mara means often, repeatedly, again and again, or from time to time, depending on context.

It is a common expression for repeated action. Very literally, mara can mean time or occasion, so the full phrase gives the sense of something happening on multiple occasions.

In this sentence, it reinforces the idea that Rahma calls her grandmother regularly.

Both of them point to repeated action, but they do slightly different jobs:

• hu- marks the verb as habitual
• mara kwa mara adds an adverbial idea like often / repeatedly / regularly

Using both together is natural. It makes the habit clearer and a bit more emphatic.

So the sentence is not just saying that Rahma is someone who calls her grandmother as a general habit; it also highlights that she does it frequently or repeatedly.

Yes. A very common alternative is:

• Rahma humpigia bibi yake simu.

This uses the verb -pigia, which is very common when you do something to/for someone, and it can include the object marker m- for the person being called.

Both sentences are natural, but learners will often hear the -pigia mtu simu pattern in everyday Swahili.

The given order is natural:

• Rahma hupiga simu kwa bibi yake mara kwa mara.

But Swahili word order can be somewhat flexible, especially with adverbial phrases. For example, mara kwa mara could be placed a little differently for emphasis.

Still, for a learner, the safest thing is to keep the sentence in the original order until you get more comfortable with the language.

Also, unlike English, Swahili has no articles like a, an, or the, so nouns like simu and bibi appear without them.