Learn Hardcore Swahili: Nilimletea leso mpya yenye maua mekundu kama zawadi ya siku ya kuzaliwa. - I brought her a new headscarf with red flowers as a birthday gift.

Nilileta leso mpya... – I brought a new handkerchief... (just stating that you brought it)
Nilimletea leso mpya... – I brought a new handkerchief *for him/her...*

So kuletea is chosen because the sentence is about bringing the handkerchief as a gift for someone.

Is the object marker -m- in Nilimletea necessary? What changes if I say Nililetea leso mpya... instead?

The object marker -m- marks a specific person (him/her) who is already known in the context.

Nilimletea leso mpya...
= I brought (for) him/her a new handkerchief...
The recipient is definite and understood from the context.
Nililetea leso mpya...
= I brought a new handkerchief (for someone / for a person).
Grammatically okay, but the person is not specified inside the verb. You’d usually then name them:
- Nililetea Maria leso mpya... – I brought Maria a new handkerchief...

In the original sentence, because no separate noun like "Maria" appears, -m- is doing all the work of expressing "for him/her." Dropping it would make the recipient vague.

What exactly is a leso? Is it a handkerchief or a scarf?

Leso is a common East African word for a piece of cloth, often:

a headscarf or wrap women tie around their head or waist
a brightly patterned square of fabric (similar to a bandana)
sometimes just translated as handkerchief depending on context

Grammar-wise:

Class: usually noun class 9/10
Singular: leso moja – one leso
Plural: most commonly leso again, e.g. leso mbili – two lesos

In this sentence, from context, it’s natural to understand it as something like a decorative handkerchief / scarf.

Why is it leso mpya and not mpya leso?

In Swahili, adjectives usually follow the noun they describe.

leso mpya – a new handkerchief
kitabu kizuri – a good book
mtoto mdogo – a small child

So mpya leso would be wrong in standard Swahili. The normal order is:

noun + adjective
leso mpya, not mpya leso

How does the adjective mpya agree with leso?

The base adjective is -pya = new.
It changes form depending on the noun class.

Leso belongs to noun class 9 (N-class), which often uses an m-/n-/ny- type prefix on adjectives beginning with -pya, -zuri, -refu, etc.

So you get:

leso mpya – a new handkerchief (class 9)
siku mpya – a new day (also class 9)
habari mpya – new news/information (class 9)

Compare other classes:

mtoto mpya (class 1) – a new child
vitabu vipya (class 8) – new books
maua mapya (class 6) – new flowers

So mpya is the correct agreement form with leso.

What does yenye mean in leso mpya yenye maua mekundu? How is it different from ambayo ina?

yenye can be understood as “having / with”.

leso mpya yenye maua mekundu
≈ leso mpya ambayo ina maua mekundu
= a new handkerchief that has red flowers / with red flowers on it

Difference in feel:

ambayo ina = literally which has; a bit longer and more explicit
yenye = shorter, more compact “with / having”

Both are correct, but yenye + [noun phrase] is very common in spoken and written Swahili when you want to say something like “X with Y”:

gari lenye rangi nyekundu – a car with red color
nyumba yenye dirisha kubwa – a house with a big window

Does yenye agree with leso? What would it look like with other noun classes?

Yes. Yenye is a relative/possessive form that must agree with the noun class of the noun it refers to.

Here it refers to leso (class 9), so we use:

leso mpya yenye maua mekundu – a new handkerchief with red flowers

Some other common forms:

Class 1 (mtu): mtu mwenye pesa – a person with money
Class 2 (watu): watu wenye pesa – people with money
Class 5 (gari): gari lenye matatizo – a car with problems
Class 6 (magari): magari yenye matatizo – cars with problems
Class 7 (kitu): kitu chenye thamani – something that has value
Class 8 (vitu): vitu vyenye thamani – things that have value
Class 9/10 (leso/leso, nyumba/nyumba): nyumba yenye dirisha – a house with a window

For class 9/10 nouns (like leso and nyumba), the agreeing form is yenye.

Why is it maua mekundu and not maua nyekundu?

The base adjective for red is -ekundu.
It changes shape according to the noun class.

The noun ua (a flower) is class 11; its plural maua is class 6. For class 6 plurals (ma-), -ekundu usually shows up as mekundu:

ua jekundu – a red flower (singular, class 11)
maua mekundu – red flowers (plural, class 6)

Other examples with class 6:

mayai mekundu – red eggs
matunda mekundu – red fruits

You will also hear nyekundu used pretty widely with many nouns, and in everyday speech some speakers don’t strictly follow all these agreement changes. But maua mekundu is textbook‑correct agreement for class 6.

In kama zawadi ya siku ya kuzaliwa, what does kama mean? Is it “if” or “like”?

Here kama means “as” in the sense of “in the role of / functioning as”:

kama zawadi ya siku ya kuzaliwa
= as a birthday present

So the structure is:
Nilimletea ... kama zawadi... – I brought (it) to him/her *as a gift...*

Other common uses of kama:

like / as (comparison)
- Anaimba kama ndege. – She sings like a bird.
if (in some conditional sentences)
- Kama unataka, naweza kukusaidia. – If you want, I can help you.
about / approximately (with numbers)
- Walikuwa kama watu mia. – They were about a hundred people.

In your sentence, only the “as (a gift)” meaning fits.

How is siku ya kuzaliwa structured? What does it literally mean?

Break it down:

siku = day
ya = of (possessive/associative for class 9 nouns like siku)
kuzaliwa = being born / birth
- ku- (infinitive/gerund marker) + zaliwa (to be born, passive verb)

So siku ya kuzaliwa literally means:

“the day of being born”

which is exactly what “birthday” is in English.

Grammatically, kuzaliwa acts here like a noun (“birth”).

Why are there two ya’s in kama zawadi ya siku ya kuzaliwa?

The whole phrase is:

kama zawadi ya siku ya kuzaliwa

Structure:

zawadi ya siku
- zawadi (gift, class 9)
- ya (of, agreeing with zawadi)
  → a gift of a day / a day’s gift
siku ya kuzaliwa
- siku (day, class 9)
- ya (of, agreeing with siku)
- kuzaliwa (being born)
  → the day of birth

So you have a chain of “of” relationships:

zawadi ya siku ya kuzaliwa
= a gift of the day of birth
= a birthday present

Each ya agrees with the noun immediately before it:

zawadi (9) → ya
siku (9) → ya

Can I change the word order, for example move the birthday phrase earlier in the sentence?

Yes, Swahili word order is fairly flexible, as long as related parts stay together and the verb slot is respected.

Your original:

Nilimletea leso mpya yenye maua mekundu kama zawadi ya siku ya kuzaliwa.

Some acceptable variations:

Kama zawadi ya siku ya kuzaliwa, nilimletea leso mpya yenye maua mekundu.
As a birthday present, I brought him/her a new handkerchief with red flowers.

You could also slightly move the phrase but usually you keep the whole noun phrase leso mpya yenye maua mekundu together:

❗Nilimletea kama zawadi ya siku ya kuzaliwa leso mpya yenye maua mekundu.
This can be understood, but feels awkward: the verb letea normally wants its direct object (what you brought) right after it.

Most natural patterns:

[Verb] [object phrase] [extra info phrase]
→ Nilimletea leso mpya yenye maua mekundu kama zawadi ya siku ya kuzaliwa.

[Extra info] [verb] [object phrase]
→ Kama zawadi ya siku ya kuzaliwa, nilimletea leso mpya yenye maua mekundu.