Learn Hardcore Swahili: Dada yangu anachagua kusoma fizikia, lakini mimi nachagua kusoma uandishi wa habari. - My sister chooses to study physics, but I choose to study journalism.

So: a + na + chagu + a → anachagua.
Swahili usually doesn’t use a separate word for “is” here; the tense marker -na- inside the verb covers that idea.

Why is it nachagua and not ninachagua for “I choose / I am choosing”?

The “full” textbook form is:

ninachagua = ni- (I) + -na- (present) + -chagua (choose)

In everyday Swahili, especially in speech, ninachagua is very commonly shortened to nachagua. The ni- is dropped because ni + na is a bit heavy, and native speakers like to simplify:

ninapenda → napenda (“I like”)
ninakula → nakula (“I am eating”)
ninachagua → nachagua (“I choose / I am choosing”)

Both ninachagua and nachagua are understood. In more formal writing or exams, teachers may prefer the full ninachagua, but nachagua is very natural and common.

If nachagua already means “I choose,” why do we also have mimi? Isn’t that redundant?

Yes, strictly speaking it is redundant: nachagua already tells you the subject is “I”.

Here, mimi is used for emphasis or contrast, something like:

“…but I choose…”
Swahili nuance: “lakini mimi nachagua…” = “but as for me, I choose…”

So:

Nachagua kusoma uandishi wa habari. = I choose to study journalism.
Lakini mimi nachagua kusoma uandishi wa habari. = But I, on the other hand, choose to study journalism.

Swahili often uses mimi, wewe, yeye, sisi, ninyi, wao not to show who does the action (the verb already does that) but to highlight or contrast the person.

What is kusoma doing here, and what form of the verb is it?

kusoma is the infinitive, meaning “to study / to read”.

Structure:

ku- = infinitive marker “to …”
-som- = root “read / study”
-a = final vowel

So kusoma = “to study / to read”.

After verbs like:

kuchagua (to choose)
kupenda (to like)
kutaka (to want)
kujaribu (to try)

Swahili normally uses ku + verb, e.g.:

anachagua kusoma fizikia = she is choosing to study physics
nataka kusoma Kiswahili = I want to study Swahili
anapenda kuimba = she likes to sing

Do I really need to repeat kusoma in the second part, or can I say:
Dada yangu anachagua kusoma fizikia, lakini mimi nachagua uandishi wa habari.?

You can omit the second kusoma, and the sentence will still be grammatically correct:

Dada yangu anachagua kusoma fizikia, lakini mimi nachagua uandishi wa habari.

This is understood as:

“My sister chooses to study physics, but I choose journalism.”

However, repeating kusoma makes the parallel structure very clear:

…anachagua kusoma fizikia, lakini mimi nachagua kusoma uandishi wa habari.

Both are natural. Repeating kusoma is slightly clearer and more emphatic about the “study” part in both halves.

What exactly does uandishi wa habari mean, and how is it formed?

uandishi wa habari literally means “the writing of news”, and in practice it means journalism.

Breakdown:

kuandika = to write
From this verb we get the abstract noun uandishi:
- u- = noun prefix that often makes abstract nouns from verbs
- -andishi (from -andika) = “writing / authorship”
- So uandishi = “(the act/practice of) writing”
wa = “of” (linking word showing possession/association)
habari = news, information, reports

Together:

uandishi wa habari = literally “writing of news” → journalism (the profession or field)

Is habari here “news” or “information”? I’ve also seen it used as “hi / how are you?”.

In this phrase, habari means news in the sense of information that is reported in the media.

As a noun: habari = news, information, report(s).
In greetings like Habari?, it is short for things like Habari gani?, meaning “What’s the news? / How’s everything?” — so it becomes a way to say “How are you?”

In uandishi wa habari, the common, accepted meaning is “journalism” (news writing / news reporting), not just general information.

How does dada yangu work, and how would I say “my older sister” or “my younger sister”?

dada yangu means “my sister”.

Breakdown:

dada = sister (usually older, but can be general “sister / big sister”)
yangu = “my”, agreeing with dada, which is in noun class 9/10

Possession in Swahili is usually noun + possessive:

rafiki yangu = my friend
nyumba yangu = my house
dada yangu = my sister

To specify older/younger:

dada yangu mkubwa = my older/big sister
dada yangu mdogo = my younger/little sister

For plural “my sisters”:

dada is both singular and plural; you show plural with the possessive:
- dada zangu = my sisters (here zangu is the plural possessive agreeing with class 10).

Where is the word “is” in this sentence? English says “is choosing,” but I don’t see a separate “is” in Swahili.

In Swahili, “is” is usually built into the verb via the tense marker, not a separate word.

anachagua = a- (she/he) + -na- (present tense) + chagua (choose)
The -na- here carries the meaning that English would express with “is … -ing” or simple present.

So:

Dada yangu anachagua kusoma fizikia.
= “My sister is choosing to study physics”
or “My sister chooses to study physics.”

Swahili does have ni as a copula “is/are” in some contexts:

Dada yangu ni mwandishi. = My sister is a writer.

But with verbs of action like kuchagua, you don’t add a separate “is”; you show tense inside the verb with things like -na-, -li-, -ta-, etc.

How would I change the tense of anachagua to say “chose” or “will choose”?

You change the tense marker inside the verb:

Present (is choosing / chooses)
- anachagua = a- (she/he) + -na- (present) + chagua
Past (chose)
- alichagua = a- + -li- (past) + chagua
- Dada yangu alichagua kusoma fizikia.
  = My sister chose to study physics.
Future (will choose)
- atachagua = a- + -ta- (future) + chagua
- Dada yangu atachagua kusoma fizikia.
  = My sister will choose to study physics.

Same pattern for I:

Present: ninachagua / nachagua
Past: nilichagua
Future: nitachagua

What does lakini do, and can I use another word like ila instead?

lakini is a conjunction meaning “but”.

In the sentence:

…anachagua kusoma fizikia, lakini mimi nachagua…
= “…is choosing to study physics, but I choose…”

You can often use ila in a similar way:

Dada yangu anachagua kusoma fizikia, ila mimi nachagua kusoma uandishi wa habari.

Both are understood, but:

lakini = the most common, neutral “but” in standard Swahili.
ila = can mean “but / except / only that”, and may sound a bit more conversational in some contexts.

Here, lakini is the safest, most standard word for “but.”

Is fizikia just a loanword for “physics,” and does it need a capital letter in Swahili?

Yes, fizikia is a loanword from English “physics” (via other languages), adapted to Swahili spelling and pronunciation.

Pronounced roughly fi-zi-ki-ya.
It is a school subject / field of study, just like kemia (chemistry), hisabati (mathematics), etc.

Capitalization:

In many Swahili texts, subjects and common fields like fizikia, kemia, hisabati, historia are not capitalized unless they start the sentence.
Proper nouns (names of people, countries, etc.) are capitalized.

So fizikia written in lowercase inside the sentence is perfectly normal in Swahili.