Learn Hardcore Swahili: Mama anawasha mshumaa sebuleni usiku. - Mother lights a candle in the living room at night.

So anawasha literally means “he/she is lighting” or “he/she lights”.
In this sentence: Mama anawasha mshumaa… → Mother is lighting a candle… / Mother lights a candle…

In English we say “a/the candle” and “in the living room”. Why is there no “a/the” in Swahili?

Swahili does not use articles like “a, an, the”.
Nouns stand bare, and context tells you whether English should use a or the.

mshumaa can mean a candle or the candle
sebule / sebuleni can mean (the) living room

So Mama anawasha mshumaa sebuleni could be translated as:

“Mother is lighting a candle in the living room”
“Mother is lighting the candle in the living room”

Both are possible depending on context, even though the Swahili sentence stays the same.

What does mshumaa mean exactly, and what is its plural?

Mshumaa means candle.

It belongs to the m-/mi- noun class (class 3/4).
So:

Singular: mshumaa = a candle
Plural: mishumaa = candles

Example:

Kuna mshumaa mezaani. – There is a candle on the table.
Kuna mishumaa mezaani. – There are candles on the table.

Why is it sebuleni and not just sebule?

Sebule means living room.
When you add -ni to many nouns, it creates a locative form meaning in/at/on [that place].

sebule = living room
sebuleni = in the living room / at the living room

So Mama anawasha mshumaa sebuleni literally has “living-room-in”, which we translate as “in the living room”.

Does sebuleni mean “to the living room” as well as “in the living room”?

Primarily, sebuleni means “in/at the living room”.

For direction to the living room, you would usually say:

Anaenda sebule. – She is going to the living room.

However, in fast or casual speech, a locative with -ni can sometimes feel directional in context, but the basic meaning of sebuleni is a location (in/at), not a direction (to).

How do we know anawasha is present tense? Could it also mean “she lights (habitually)”?

The present tense in Swahili uses -na-:

a- (she) + -na- (present) + washa (light)
→ anawasha

This form usually covers both:

Right now: “She is lighting a candle.”
General/habitual (depending on context): “She lights a candle.”

Swahili has a special habitual marker hu-, e.g.
Mama huwasha mshumaa sebuleni usiku. – Mother (usually) lights a candle in the living room at night.
But anawasha can still be understood as present or present-habitual from context.

What is the basic word order in this sentence? Can we move usiku (at night) or sebuleni (in the living room)?

The basic order here is:

Subject – Verb – Object – Place – Time

Mama (subject)
anawasha (verb)
mshumaa (object)
sebuleni (place)
usiku (time)

You can move the time expression usiku for emphasis:

Usiku, mama anawasha mshumaa sebuleni. – At night, mother lights a candle in the living room.
Mama usiku anawasha mshumaa sebuleni. – Mother, at night, lights a candle in the living room.

These are all acceptable; the meaning is mostly the same, but the focus/emphasis can shift slightly.

Does usiku need a preposition like “at night” or “in the night” in Swahili?

No preposition is needed.
Words for times of day are often used on their own as adverbs of time:

asubuhi – in the morning
mchana – in the afternoon/daytime
jioni – in the evening
usiku – at night

So Mama anawasha mshumaa sebuleni usiku already means:

“Mother lights a candle in the living room at night.”
No extra word for “at” is required.

Does mama mean specifically “my mother”, or could it just be “a woman”?

Mama in Swahili most literally means “mother / mum”, but in everyday use it can also be:

one’s own mother (often understood from context)
a respectful term for an adult woman, like “Ma’am” or “Madam”
a title plus name: Mama Asha (Mother Asha / Mrs. Asha)

In this isolated sentence, Mama is best taken as “(the) mother” or “Mum”, but it could also be a polite way of referring to a woman, depending on a larger context.

How do you pronounce mshumaa and sebuleni?

mshumaa:

Syllables: m-shu-maa
The msh is a consonant cluster: say m then sh quickly together.
-aa at the end is a long “a” sound, like “aah” held slightly longer.

sebuleni:

Syllables: se-bu-le-ni
Stress is usually on the second-last syllable: se-bu-LE-ni.
All vowels are pure (no diphthongs):
e as in “bet”, u like “oo” in “food”, e again, i like “ee” in “see”.