Learn Hardcore Swahili: Rahma hajawahi kuchelewa darasani; ndiyo maana mwalimu anamtegemea. - Rahma has never been late to class; that’s why the teacher relies on her.

Meaning: hajawahi = she has never (up to now).
Morphology: ha- (3rd person singular negative subject) + -ja- (perfect aspect in the negative) + wahi (verb: to be in time/manage to; in negation it conveys “ever”).
It’s a set phrase that functions like “has never” before another verb in the infinitive.
Other persons: sijawahi (I have never), hujawahi (you sg.), hajawahi (he/she), hatujawahi (we), hamjawahi (you pl.), hawajawahi (they).

Why is the next verb in the infinitive (kuchelewa)? Could I say hajawahi chelewa?

After (ha)jawahi, Swahili uses the infinitive (ku- + verb). So: hajawahi kuchelewa is the correct pattern. Saying hajawahi chelewa is ungrammatical. Think of hajawahi as “has never [to] …” which must be followed by the infinitive:

Sijawahi kwenda (I’ve never gone).
Umewahi kula sushi? (Have you ever eaten sushi?)

How is hajawahi kuchelewa different from hajachelewa?

Hajawahi kuchelewa: she has never been late (not even once up to now).
Hajachelewa: she hasn’t been late (this time/so far/at some specific reference time). Use hajawahi for a lifetime-to-date “never,” and hajachelewa for a situational “hasn’t been late.”

How is hajawahi kuchelewa different from hachelewi?

Hajawahi kuchelewa looks back over time and says “never (ever) been late up to now.”
Hachelewi means “she doesn’t get late / she isn’t late (as a rule).” It’s a general/habitual claim, not a lifetime-never claim.

What does the -ni in darasani mean?

The suffix -ni is a locative marker meaning “in/at/to.”

darasa = class/classroom; darasani = in class/in the classroom.
Similar: shule → shuleni (at school), nyumba → nyumbani (at home).

Is darasani the natural way to say “late for class”? Could I use kwenye/kwa/katika instead?

Yes, kuchelewa darasani is the idiomatic way to say “be late for class.” You’ll also hear prepositions like kwenye/katika, but the -ni locative with the relevant noun (darasani, ofisini, kanisani) is very natural here.

What does ndiyo maana mean, literally and idiomatically?

Literally: ndiyo (it is indeed/yes) + maana (meaning/reason).
Idiomatically: that’s why / that is the reason.
Near-synonyms: ndiyo sababu, kwa hiyo/kwa hivyo (“therefore/so”), basi (“so/then,” more conversational).

Why is there a semicolon before ndiyo maana? Could I use a period or comma?

A semicolon neatly links two closely related clauses (cause → result) without starting a new sentence. A period would also be fine, or a comma if you add a conjunction/connector (e.g., …, kwa hiyo …). Swahili punctuation practices are broadly similar to English here.

How is anamtegemea built, piece by piece?

a- (3rd person singular subject, “he/she”)
-na- (present/habitual tense-aspect)
-m- (object marker “him/her”)
tegemea (verb “rely on/expect from/depend on”)
So anamtegemea = “he/she relies on her/him.” In the sentence, the subject is mwalimu (the teacher), and the object “her” refers back to Rahma.

Do I have to include the object marker -m- here? Could I say Mwalimu anategemea Rahma?

When the object is explicitly named after the verb (e.g., Rahma), Standard Swahili often omits the object marker: Mwalimu anategemea Rahma.
When the object is understood/pronominal (no full noun repeated), you use the object marker: Mwalimu anamtegemea (“the teacher relies on her”).
Using both the object marker and a following full noun (clitic doubling) occurs in some varieties for emphasis but is often avoided in careful Standard Swahili.

Does kutegemea mean “rely on,” “depend on,” or “expect from”? Which fits best here?

Kutegemea can mean all three, depending on context: rely on, depend on, count on, or expect (from). Here, given Rahma’s perfect record, “rely on / count on” is the most natural reading, though “the teacher has high expectations of her” is also plausible.

Could I use the habitual marker hu- instead of ana- in anamtegemea?

Yes, to express a general habit, you can say: Mwalimu humtegemea (the teacher relies on her, generally).
Notes:

hu- marks habitual and does not take a subject prefix (you don’t say “ahu-”).
hu- is only affirmative; for a negative habitual you’d use standard negation (e.g., Mwalimu hamtegemei = the teacher does not rely on her).

How would I ask, “Has Rahma ever been late to class?”

Use am(e)wahi for “ever” in questions:

Je, Rahma amewahi kuchelewa darasani? (Has Rahma ever been late to class?)
Answer patterns: Hajawahi (Never), or Ndiyo, amewahi (Yes, she has).

If I want to put the second clause in the past, how would I say “That’s why the teacher relied on her (then)”?

Change the verb to past: Ndiyo maana mwalimu alimtegemea.

a- (he/she) + -li- (past) + -m- (her/him) + tegemea → alimtegemea (“relied on her”).
You could also say: Ndiyo maana mwalimu alimtegemea wakati huo (… at that time), if you want to anchor it in a specific past period.

Do I need to say a separate pronoun like yeye for “she” in the first clause?

No. Swahili encodes the subject on the verb, so hajawahi already means “she has never.” You could add Yeye for emphasis or contrast: Yeye hajawahi kuchelewa darasani (She, on the other hand, has never been late), but it’s not required.