Learn Hardcore Hausa: A bayan gidanmu akwai kaji da akuya guda biyu. - Behind our house there are chickens and two goats.

A is a general preposition meaning in / at / on, used for locations.
Bayan comes from baya (back) and here means behind / at the back of.

So a bayan gidanmu literally means at the back/behind our house.
You will also hear bayan gidanmu without a; both are common and grammatical, with a just making the location sense very clear.

How is gidanmu formed? Why isn’t it gida mu as two words?

Gidanmu breaks down like this:

gida – house
-n – a linking sound (genitive linker)
mu – we / our

So gidanmu = our house (literally: house-of-us).
You can’t say gida mu as two separate words; the possessive pronoun must attach to the noun (with the linking -n here).

What exactly is akwai? Is it a verb like “there is/are,” and does it change for singular or plural?

Akwai is an existential verb meaning roughly there is / there are / exist / be present.
It does not change for singular vs. plural:

Akwai akuya. – There is a goat.
Akwai awaki. – There are goats.

It also doesn’t change its form for tense; you show tense with other words around it (time expressions, context, etc.).

Why doesn’t Hausa use a separate word for “there” in “there are…”?

In English, there in there is / there are is mostly a grammatical filler.
In Hausa, that function is handled entirely by akwai, plus the location phrase.

So instead of saying “There are chickens behind our house”, Hausa says literally “At the back of our house exist chickens …”:
A bayan gidanmu akwai kaji…

Can I also say Akwai kaji da akuya guda biyu a bayan gidanmu? Is that still correct?

Yes, that is correct and natural. Both patterns are common:

A bayan gidanmu akwai kaji… (location first, then akwai)
Akwai kaji… a bayan gidanmu (akwai
- things first, then location)

Putting the location first can emphasize the place; putting akwai first can emphasize the existence of the animals. In everyday speech, both orders are used freely.

Is kaji singular or plural? What is the singular form?

Kaji is plural. The singular is kaza (a chicken).

kaza – a chicken
kaji – chickens

So here kaji means chickens (some chickens, not specified how many).

Why is akuya singular if the meaning is “two goats”?

In Hausa, when you explicitly count things, the noun can stay in the singular, and the number shows that it is plural in meaning.

Here:

akuya – goat (formally singular)
guda biyu – two units / two of them

Together akuya guda biyu is understood as two goats. The plural meaning comes from guda biyu, not from a plural ending on akuya.

What does guda mean in akuya guda biyu? Do I really need it?

Guda literally means something like unit / single piece / one (item).
With numbers, it works like a kind of classifier:

akuya guda biyu – two individual goats
littafi guda uku – three individual books

You can say akuya biyu without guda and it is still correct.
Using guda often makes the counting sound a bit more careful, clear, or emphatic, especially with animals and objects.

Could I instead say awaki biyu or akuyoyi biyu for “two goats”? How does that compare to akuya guda biyu?

Yes, both are possible:

awaki biyu – two goats (using one plural form awaki)
akuyoyi biyu – two goats (using another plural akuyoyi, more transparent from akuya)
akuya guda biyu – literally “goat, two (units)” → two goats

All are understandable.
Using the plural + number (e.g. awaki biyu) explicitly marks the noun as plural. Using singular + guda + number (e.g. akuya guda biyu) lets the number phrase carry the plural meaning.

What does da mean here, and is it the same da that means “with” or “has”?

In this sentence, da is a coordinating conjunction meaning and:

kaji da akuya guda biyu – chickens and two goats

The same word da is also used in other functions:

Ina da akuya. – I have a goat.
Ina tare da kai. – I am with you.

So yes, it’s the same word da, but its exact meaning is decided by context and structure.

Why is the number phrase after the noun (akuya guda biyu) instead of before it, like in English “two goats”?

In Hausa, numerals normally come after the noun they modify:

kaji uku – three chickens
mutane goma – ten people
akuya guda biyu – two goats

So the typical pattern is [noun] + (guda) + [number], not the English order [number] + [noun].

Could I also put numbers on kaji and say kaji biyu da akuya guda biyu? Would that change the meaning?

Yes, you can:

kaji biyu da akuya guda biyu – two chickens and two goats

Compared with the original kaji da akuya guda biyu:

kaji da akuya guda biyu – some chickens (unspecified how many) and two goats
kaji biyu da akuya guda biyu – two chickens and two goats

So adding a number to kaji just makes the quantity of chickens explicit.