Learn Hardcore Swahili: Hivi ndivyo vipimo vya uzito na urefu tunavyotumia kwenye mizani. - This is how the weight and height measurements we use on the scale are.

It’s a cleft/focus construction meaning roughly “these are exactly the …”. It fronts the demonstrative hivi (“these,” class 8) and uses ndivyo to emphasize identity. A plainer version without the focus would be: Hivi ni vipimo vya uzito na urefu tunavyotumia kwenye mizani.

Why are there so many pieces with vi-/vy- (hivi, ndivyo, vipimo, vya, -vyo-)?

They all agree with the noun class of vipimo (class 8, plural):

hivi = class 8 proximal “these/like this”
ndivyo = focused copula agreeing with class 8
vipimo = class 8 plural noun (“measurements/units”)
vya = “of” agreeing with class 8 head noun (vipimo)
-vyo- = class 8 relative marker inside the verb

Can you break down tunavyotumia?

Yes:

tu- = we
-na- = present/ongoing tense
-vyo- = class 8 relative marker “which/that”
-tumia = use Together: “which we use.”

Why not just say tunatumia?

Without the relative marker, tunatumia starts a new clause (“we use …”) and leaves vipimo unconnected. The relative -vyo- makes “the measurements” the object of “use” inside the same noun phrase: “the measurements that we use.”

Could I use ambavyo instead of the relative infix -vyo-?

Yes. Both are correct:

With infix: vipimo … tunavyotumia
With a relative word: vipimo … ambavyo tunatumia The -vyo- version is more compact; ambavyo can feel a bit more explicit or formal.

Why is it vya (in vya uzito na urefu) and not ya?

The associative “of” agrees with the head noun vipimo (class 8). For class 8, it’s vya. Using ya would match a different class and be ungrammatical here.

What classes are uzito and urefu, and do they affect agreement?

Uzito (“weight”) and urefu (“length/height”) are u- nouns (often class 14/11). But the agreement on vya is controlled by the head noun vipimo (class 8), not by the complements uzito and urefu.

Does urefu mean “height” or “length”? When would I use kimo?

urefu can mean length or height in general (the height/length of a person, object, or thing).
kimo is specifically a person’s stature (how tall someone is). If you mean human height, kimo is often more natural.

What does kwenye mean here? Could I use katika or juu ya instead?

kwenye is a general locative “in/at/on,” very common and natural here.
katika is more formal “in/within” and is less natural with physical surfaces like a scale.
juu ya means “on top of,” emphasizing surface contact; it’s fine if you want to be very literal: … juu ya mizani.

Is mizani singular or plural? And is mizanini OK?

In everyday use, mizani (“scale(s)”) is often treated as an invariable noun (same form for singular and plural), and context tells you which is meant. For a locative, mizanini (adding -ni) is also acceptable and common; kwenye mizani is equally idiomatic.

Could I rephrase the sentence without the cleft?

Yes:

Vipimo vya uzito na urefu tunavyotumia kwenye mizani ni hivi.
Hivi ni vipimo vya uzito na urefu tunavyotumia kwenye mizani. These have less emphasis than the clefted Hivi ndivyo …

How would it change if we were talking about a single measurement?

Use class 7 singular forms:

Hiki ndicho kipimo cha uzito tunachotumia kwenye mizani.
Hiki ndicho kipimo cha urefu tunachotumia kwenye mizani. Note the agreements: hiki/ndicho/kipimo/cha/…/tunacho-.

Why not tunayotumia instead of tunavyotumia?

Because the relative marker must match the class of vipimo (class 8 → -vyo-). -yo- is the relative marker for other classes (e.g., class 6: mavazi tunayovaa). Here it must be tunavyotumia (or use ambavyo).

Does vipimo mean “measurements” or “units”?

Both are possible depending on context. Vipimo can be:

Concrete measurements you take (readings)
Units or standards you use (e.g., kilograms, meters) The mention of mizani suggests practical measurements and/or the units used on a scale.

What’s the difference between hivi and hivyo in this pattern?

hivi = “these/like this” (proximal, class 8). Hivi ndivyo … often introduces “this is how/these are the ones …”
hivyo = “those/like that” (distal or anaphoric). Hivyo ndivyo … would mean “that’s exactly how …,” usually referring back to something just mentioned.