Learn Hardcore Swahili: Mimi ninapenda kujadili siasa na marafiki nyumbani. - I like to discuss politics with friends at home.

In Swahili, every normal verb needs a subject prefix (ni-, u-, a-, tu-, m-, wa-, etc). So ninapenda is already a complete phrase meaning I like / I love.

Adding Mimi puts extra emphasis on the subject:

Ninapenda kujadili siasa… = I like discussing politics…
Mimi ninapenda kujadili siasa… = I (personally / as for me) like discussing politics…

So it’s not “wrong” or redundant; it’s emphasis or contrast (e.g. I like it, but he doesn’t).

Can I drop Mimi and just say Ninapenda kujadili siasa na marafiki nyumbani?

Yes. That’s actually more typical in everyday Swahili.

Mimi ninapenda… – slightly emphatic: I like…
Ninapenda… – neutral: I like…

Since the subject prefix ni- already shows that the subject is “I”, Mimi is optional and used mainly:

for emphasis or contrast
at the start of a conversation to introduce yourself or your habits

What exactly does the -na- in ninapenda mean? Is this present tense, or present continuous?

In ni-na-penda:

ni- = I (subject prefix)
-na- = present tense marker
-penda = like / love

The -na- marker usually covers both:

general present / habitual: I like / I usually like / I enjoy
present progressive (for many verbs): I am doing…

With penda it’s usually more habitual/general:

Ninapenda kujadili siasa = I (generally) like discussing politics.

If you wanted a more “right now” flavor, you’d usually change the verb meaning (e.g. najadili = I’m discussing), rather than the tense marker.

Could I say Napenda kujadili… instead of Ninapenda kujadili…?

Yes, Napenda is common in speech and informal writing.

Ninapenda = full form (ni-na-penda)
Napenda = shortened form (still understood as “I like”)

Swahili often drops the vowel of ni- before another i / e / a in casual speech. In careful writing or in textbooks you’ll see ninapenda, but in everyday talk you’ll constantly hear napenda.

What is kujadili exactly? Is it an infinitive, a noun, or something else?

Kujadili is the infinitive / verbal noun form:

jadili = verb root: discuss
ku-
- jadili → kujadili = to discuss / discussing

In Swahili, the ku- infinitive can function both as:

An infinitive: Ninapenda kujadili… = I like to discuss…
A gerund-like noun: Kujadili siasa ni vizuri = Discussing politics is good.

So here kujadili is like to discuss or discussing, used as the object of ninapenda (I like…).

Why is there no word for “the” before siasa or marafiki?

Swahili has no separate words for “a/an/the”. Nouns like siasa (politics) and marafiki (friends) can mean:

politics / the politics
friends / the friends

Context tells you whether it’s general or specific:

Ninapenda kujadili siasa na marafiki nyumbani.
→ Grammatically: I like discussing politics with friends at home.
→ Could also be understood as with my friends or with the friends depending on context.

If you want to be clearly specific, you can add words like:

hawa marafiki = these friends
wale marafiki = those friends
marafiki wangu = my friends

Does na marafiki mean “and friends” or “with friends”? How does na work here?

Na in Swahili can mean both “and” and “with”. The meaning depends on context.

Here, na marafiki is best understood as “with friends”:

kujʻadili siasa na marafiki = to discuss politics with friends

Often, when na follows an activity and a person, it’s interpreted as “with”:

Ninaenda sokoni na dada yangu. = I’m going to the market with my sister.
Anacheza mpira na rafiki zake. = He’s playing football with his friends.

If you want to avoid any ambiguity, you can say pamoja na marafiki (together with friends), but usually na alone is clear.

Why is it marafiki and not something like rafiki-rafiki for plural? Is this an irregular plural?

Yes, rafiki has an irregular plural:

rafiki = friend (class 9/10)
marafiki = friends (class 6)

Instead of just using rafiki for both singular and plural, Swahili commonly uses:

rafiki (sg.)
marafiki (pl.)

So in the sentence:

marafiki clearly means friends (more than one person).

Does nyumbani mean “at home” or “to home”? How does the -ni ending change the meaning?

Nyumba = house / home.
Nyumbani = at home / in the house / to the house (depending on context).

The -ni ending often marks:

location: in / at / on
or direction: to

So:

nyumbani can mean at home, in the house, or homewards/to home.

In your sentence:

…na marafiki nyumbani.
→ Best understood as with friends at home (a location).

If you wanted to stress movement, you might say:

Ninarudi nyumbani. = I’m going back home / returning home.

Is the word order flexible? Could I say Ninapenda kujadili na marafiki siasa nyumbani instead?

Swahili word order is more flexible than English, but not everything sounds natural.

The usual and most natural order here is:

[verb] [infinitive] [object] [with whom] [place]
Ninapenda kujadili siasa na marafiki nyumbani.

Your alternative:

Ninapenda kujadili na marafiki siasa nyumbani

is understandable, but sounds less natural, because you’re splitting kujʻadili from its direct object siasa. Swahili normally keeps the object close to the verb:

Good: kujadili siasa na marafiki nyumbani
Odd: kujadili na marafiki siasa nyumbani

Keep siasa right after kujadili in most cases.

If I want to say “I like discussing politics with my friends at home”, how do I add “my”?

You add a possessive adjective after the noun:

marafiki wangu = my friends

So the sentence becomes:

Mimi ninapenda kujadili siasa na marafiki wangu nyumbani.
or more naturally without Mimi:
Ninapenda kujadili siasa na marafiki wangu nyumbani.

Structure:

marafiki = friends
-angu = my → wangu (agreeing with the noun class of marafiki)

Can ninapenda kujadili siasa also mean “I love to talk about politics” (not just “discuss”)?

Yes, penda covers both “like” and “love” depending on context and intensity:

ninapenda = I like / I love
kujadili = to discuss / to debate (more formal/intellectual than just to talk)

For casual “talk about”, many speakers also use kuongea kuhusu siasa or kuongea juu ya siasa (to talk about politics).

But in most learning contexts, Ninapenda kujadili siasa can be translated naturally as either:

I like discussing politics
I love discussing politics

depending on how strong you want it to sound in English.