Learn Hardcore Hausa: Yara suna koya yadda za su zaɓi abokai masu kyau. - Children are learning how to choose good friends.

Main clause: Yara suna koya… – The children are learning… (present/progressive)
Subordinate clause: …yadda za su zaɓi abokai masu kyau. – …how they will choose good friends. (future)

So the full idea is: “The children are (now) learning how they will choose good friends (in the future).”

Using suna for the main action and za su inside the “how”-clause is completely normal in Hausa.

What exactly does koya mean here? Doesn’t koya also mean “to teach”?

koya is a bit flexible:

koya = to learn
koya / koyar da = to teach (especially koyar da)

So:

Ina koya Hausa. – I am learning Hausa.
Ina koyar da yara Hausa. – I am teaching the children Hausa.

In your sentence Yara suna koya yadda…, the subject is yara (children), so it must mean “are learning”, not “are teaching”. They are learning how to choose friends, not teaching anyone.

Could I also say Yara suna koyon yadda za su zaɓi… instead of Yara suna koya yadda za su zaɓi…?

Yes, that is also correct and quite natural.

koya = finite verb “to learn”
koyo = verbal noun “learning”
koyon yadda… = the learning of how…

Two common patterns are:

Yara suna koya yadda za su zaɓi abokai masu kyau.
Yara suna koyon yadda za su zaɓi abokai masu kyau.

Both mean essentially the same thing. The second one treats koyo as a noun: “The children are (in) the learning of how they will choose good friends.”

What does yadda mean, and how is it different from yaya (“how”)?

Both relate to “how”, but they are used differently:

yaya
- Used for direct questions:
  - Yaya kake? – How are you?
  - Yaya zan yi wannan? – How will I do this?
yadda
- Means “how / the way (that)” inside a statement or embedded clause:
  - Ka koya min yadda zan yi wannan. – Teach me how I will do this.
  - Na ga yadda suka yi shi. – I saw how they did it.

Your sentence has yadda za su zaɓi…, which is a “how”-clause inside a statement, so yadda is the correct choice, not yaya.

In za su zaɓi, what does za do? Could I just say su zaɓi?

za is the future marker in Hausa.

za su zaɓi = they will choose

Breaking it down:

su zaɓi by itself is more like a subjunctive/jussive form, used after certain verbs or for wishes/commands, e.g.:
- Ina so su zaɓi abokai masu kyau. – I want them to choose good friends.

To talk about a straightforward future event, you normally need za:

Za su zaɓi abokai masu kyau. – They will choose good friends.

So in your sentence, yadda za su zaɓi… = how they will choose…

What is the singular of abokai, and why is it abokai here and not something like abokan?

aboki = (a) friend (singular)
abokai = friends (plural)

The plural is formed by changing -i to -ai in this noun.

abokan is a different form: it’s the genitive / possessive form, meaning “friends of …”:

abokan aiki – workmates / colleagues (friends of work)
abokan gida – housemates

In your sentence, you just need “friends” as a direct object, so the plain plural abokai is correct:

za su zaɓi abokai – they will choose friends

How do you pronounce the ɓ in zaɓi, and what kind of sound is it?

The letter ɓ represents a voiced bilabial implosive – a sound that doesn’t exist in standard English.

Approximate tips:

Start as if you’re going to say b, with both lips together.
Slightly pull air inward into your mouth (instead of pushing it out) as you voice it.
It feels like a “swallowed b.”

So:

zaɓi is not the same as zabi with a normal b.
Roughly, English speakers can aim for something between “zabi” and “za-bi” with a bit of a “gulp” at the ɓ.

Native speakers will still understand you if you use a plain b, but knowing it’s a special sound helps you recognize it and work toward more natural pronunciation.

What does masu kyau literally mean, and why not just say abokai kyau for “good friends”?

masu kyau is a common way to form an adjective phrase in Hausa:

mai / masu = “one(s) who have / possessing”
kyau = beauty / goodness

So:

abokai masu kyau = “friends who have goodness/beauty” → good friends

You cannot say ✗ abokai kyau; that is ungrammatical. With kyau, you normally use mai/masu:

aboki mai kyau – a good friend (singular)
abokai masu kyau – good friends (plural)

So masu kyau here is functioning like an adjective “good” attached to abokai.

When do I use mai vs masu, as in aboki mai kyau and abokai masu kyau?

It depends on number:

mai – for singular nouns
masu – for plural nouns

Examples:

gida mai kyau – a good house
gidaje masu kyau – good houses
mutum mai hankali – a sensible / intelligent person
mutane masu hankali – sensible / intelligent people
aboki mai kyau – a good friend
abokai masu kyau – good friends

So your sentence correctly uses masu because abokai is plural.

Could I say Yara sun koya yadda za su zaɓi abokai masu kyau instead? How would that change the meaning?

Yes, that is also correct, but the aspect changes:

Yara suna koya… – The children are learning… (ongoing process)
Yara sun koya… – The children have learned… (the learning is completed)

So:

Yara sun koya yadda za su zaɓi abokai masu kyau.
→ The children have learned how they will choose good friends.

Your original sentence focuses on the process happening now; the version with sun describes it as already done.

Is the word order fixed? Could I say Yara suna koya yadda za su zaɓi masu kyau abokai?

The word order is essentially fixed here.

In Hausa, descriptive phrases like masu kyau normally come after the noun they modify:

abokai masu kyau – good friends
mutane masu arziki – rich people
gidaje masu tsada – expensive houses

Putting masu kyau before abokai (✗ masu kyau abokai) or separating them (✗ za su zaɓi masu kyau abokai) is ungrammatical or at least very unnatural.

So you should keep:

…za su zaɓi abokai masu kyau. ✅