Learn Hardcore Swahili: Mwalimu alieleza jinsi unavyopaswa kuandika barua pepe kwa heshima. - The teacher explained how you should write an email respectfully.

jinsi means “the way/how.”
After jinsi, Swahili uses a relative marker for “the way in which,” which here is -vyo- (the “manner” relative).
The pattern is: Subject + Tense + Relative (-vyo-) + Verb.
In the sentence: u-na-vyo-paswa kuandika = “the way you should write.”
You can also add the explicit relative word: jinsi ambavyo unapaswa kuandika (equally correct, a bit more formal/explicit).

Why isn’t it just jinsi unapaswa kuandika? Is -vyo- required?

In careful standard Swahili, after jinsi you normally include either -vyo- (inside the verb) or ambavyo. So:

Preferred: jinsi unavyopaswa kuandika or jinsi ambavyo unapaswa kuandika.
You will hear jinsi unapaswa kuandika colloquially, but it’s less careful/standard.

What’s the difference between jinsi unavyopaswa kuandika and jinsi ya kuandika?

jinsi unavyopaswa kuandika = “the way you ought/are expected to write” (normative: there’s a right way).
jinsi ya kuandika = “how to write” (neutral/instructional). Both are fine, but they don’t express the same nuance.

Break down unavyopaswa morphologically and show person changes.

u- = 2nd person singular subject “you (sg)”
-na- = present tense
-vyo- = relative marker for “the way in which”
paswa = “to be required/ought (to)” So: u-na-vyo-paswa.

Other persons:

ninavyopaswa (I), anavyopaswa (he/she), tunavyopaswa (we),
mnavyopaswa (you pl.), wanavyopaswa (they).

Could I use lazima or takiwa instead of paswa? What’s the nuance?

lazima uandike = “you must write” (strong obligation/necessity).
unapaswa kuandika = “you should/ought to write” (normative, somewhat formal).
unatakiwa kuandika = also “you should/are required to write” (very common in speech; some feel it’s slightly less formal than paswa). All are acceptable; choose based on strength and register.

Why is there kuandika after paswa? Could I say uandike instead?

With paswa, the standard pattern is paswa + infinitive:

unapaswa kuandika (you should write). Using the subjunctive (uandike) is not the usual pairing with paswa. Compare:
lazima uandike (must) vs. unapaswa kuandika (should).

What exactly does kwa heshima convey? Are there other natural options for “politely/formally”?

kwa heshima = “respectfully,” implying deference and polite tone. Other options, depending on nuance:
kwa adabu (politely, with good manners),
kwa staha (with decorum),
kwa unyenyekevu (humbly),
kwa rasmi (formally),
kwa kitaalamu (professionally).

Where should kwa heshima go in the sentence? Can I move it?

It most naturally comes at the end of the verb phrase it modifies:

… kuandika barua pepe kwa heshima. You could place it earlier for emphasis, but common, smooth word order keeps manner phrases like this toward the end.

Why isn’t there an object marker for barua pepe? When would I use one?

There’s no object marker because the teacher is talking about writing an email in general (not a specific, previously mentioned one).
Use an object marker when the object is definite/known:

… jinsi unavyopaswa kuiandika barua pepe hiyo.
Here -i- is the class 9 object marker referring to that specific email (barua pepe hiyo).

Is barua pepe one word or two? How do I pluralize “email” in Swahili?

You’ll see both barua pepe (two words) and baruapepe (one word); both are accepted in different standards. Two words are very common.
Plural: barua is class 9/10, so singular and plural look the same. Use numerals or adjectives to show number:
- barua pepe moja/mbili/nyingi.
  You may also see barua za pepe, but barua pepe mbili is more common.

Can I replace jinsi with namna or vile? Any difference?

Yes:

namna unavyopaswa… ≈ jinsi unavyopaswa… (both “the way/how”).
vile unavyopaswa… is also used; vile often points back to something known or just-mentioned (“the way in which…”). All are natural; jinsi/namna are the safest for general “how/the manner.”

Does unavyopaswa refer to a specific “you” or a generic “you”? How would I address a group?

unavyopaswa is 2nd person singular, which can be specific or generic (“you” meaning “one”).
To address a group: mnavyopaswa (you plural).
Example: Mwalimu alieleza jinsi mnavyopaswa kuandika…

Could I say Mwalimu alifundisha instead of alieleza? What’s the difference?

alieleza = “explained” (clarifying how/why, giving an explanation).
alifundisha = “taught” (imparted a skill or lesson).
Both can fit; choose based on whether you want to stress explanation or instruction.

Is there a version without the relative marker, maybe using kuwa?

Yes, but it changes the meaning:

Mwalimu alieleza kuwa unapaswa kuandika barua pepe kwa heshima.
= “The teacher explained that you should write a polite email” (a fact/obligation, not the manner). For “how to,” use either:
jinsi unavyopaswa kuandika… or
jinsi ya kuandika…

Any quick pronunciation tips for alieleza and unavyopaswa?

alieleza: say all vowels clearly: a-li-e-le-za (no diphthongs; each vowel has its own beat).
unavyopaswa: u-na-vyo-pas-wa. Keep vyo as one syllable [vyo], and don’t reduce vowels.