Learn Hardcore Swahili: Wakati unasafiri, tumia nambari ya dharura ikiwa taa za gari zitazimika ghafla. - When you are travelling, use the emergency number if the car lights suddenly go off.

wakati is a conjunction meaning “when”. It introduces a temporal clause—here, “when you are traveling.” After wakati, you still use a fully inflected verb (unasafiri) to show subject and tense.

How is the verb unasafiri formed?

unasafiri breaks down as:

u- = subject marker for you (singular)
-na- = present-tense/aspect marker (habitual or ongoing)
safiri = verb stem “travel”
Altogether it means “you are traveling” or simply “you travel.”

Why do we say nambari ya dharura instead of nambari wa dharura or another form?

Swahili uses noun-class agreement for possession. nambari (“number”) belongs to the N-class (class 9/10), whose singular genitive/possessive linker is ya. That’s why nambari ya dharura literally means “number of emergency” (i.e. emergency number).

What role does ikiwa play in ikiwa taa za gari zitazimika ghafla?

ikiwa means “if” in conditional clauses. It combines the relative marker i- with -ki and is used with the verb in its normal form (with subject and tense). You could also form a conditional with the -ki- infix and drop ikiwa, for example:
Tumia nambari ya dharura, taa za gari zikizimika ghafla.

Why is the verb zitazimika in the future tense, and what do its parts mean?

zitazimika =

zi- = subject marker for class 10 (plural) nouns like taa (“lights”)
-ta- = future-tense marker (“will…”)
-zimika = reflexive stem of “go out”
So zitazimika means “they (the lights) will go out.” Using the future in a conditional emphasizes a possible event.

What does ghafla mean, and why is it placed after zitazimika?

ghafla means “suddenly.” In Swahili, adverbs typically follow the verb they modify, so you place ghafla right after zitazimika to express that the lights go out abruptly.