A gaba za mu koyi Hausa sosai.

Literally, a gaba is something like “at the front / ahead”. In time expressions it is used idiomatically to mean:

• later (on)
• in the future
• next / in the next stage

So in A gaba za mu koyi Hausa sosai, a gaba sets the time frame: we’re not doing it now; we’ll do it later / in the upcoming stage.

The word gaba can mean “front, ahead” in space, and by extension “ahead (in time), later, the next part”.

In this sentence, it is clearly time:
A gaba za mu koyi Hausa sosai ≈ Later / In the future, we will learn Hausa very well.

In a purely spatial sense you could also say things like a gaba na gida “in front of the house,” but here the context is about time, not location.

Yes, adverbials like a gaba are somewhat flexible. These are all possible:

• A gaba za mu koyi Hausa sosai.
• Za mu koyi Hausa sosai a gaba.

Both are grammatical. Putting a gaba at the beginning is very natural and gives it a bit of emphasis: as for later / in the future…. At the end, it’s more like you’re adding the time information after saying what you’ll do.

za is a future tense marker.
mu is the subject pronoun “we”.

Together, za mu = “we will / we are going to”.

So:

• za ni / zan – I will
• za ka – you (m.sg) will
• za ki – you (f.sg) will
• za shi / zai – he will
• za ta / zata – she will
• za mu / zamu – we will
• za ku – you (pl) will
• za su / zasu – they will

In informal writing, people often join them (e.g. zamu), but it’s the same thing.

• mu by itself is just “we” and can be used for emphasis or in some constructions like mu tafi “let’s go”.
• za mu is specifically “we will” (future tense).

So:

• Mu koyi Hausa sosai. – “Let’s learn Hausa well.” (a suggestion/command)
• Za mu koyi Hausa sosai. – “We will learn Hausa well.” (a future statement)

The basic idea is that koya / koyi is the verb “to learn” (and in some contexts “to teach”). In the future tense with za, you often see the -i form:

• Zan koyi Hausa. – I will learn Hausa.
• Za mu koyi Hausa sosai. – We will learn Hausa very well.

You may also see koya in other forms, e.g.:

• Ina koya Hausa. – I am learning Hausa.
• Na koyi Hausa. – I (have) learned Hausa.

So koya/koyi are related forms of the same verb; koyi here is the form that follows za.

No. In Hausa, a direct object typically comes without a preposition. So:

• koyi Hausa – learn Hausa
• koyi Turanci – learn English
• koyi Faransanci – learn French

Using da here (e.g. koyi da Hausa) would be ungrammatical in this meaning. Just put the language name directly after the verb.

In Hausa, Hausa can mean:

• the Hausa people
• the Hausa language

Which one it is depends on context. After koyi (“learn”), it clearly means the Hausa language:
koyi Hausa = learn Hausa (the language).

So A gaba za mu koyi Hausa sosai means “we will learn the Hausa language very well,” not “we will learn (about) Hausa people very well.”

sosai is an adverb that intensifies the action, and depending on the verb it can be translated as:

• very (much)
• really
• very well / thoroughly

In koyi Hausa sosai, it is best understood as:

• “learn Hausa very well / really well”

It doesn’t mean that Hausa itself is “very Hausa”; it strengthens how well the action of learning is done.

Other similar words:

• da kyau – well, nicely
• ƙwarai – extremely, very much
• sosai-sosai – very very much (stronger emphasis)

The usual and natural place for sosai is after the verb phrase it is intensifying, typically after the object:

• Za mu koyi Hausa sosai. ✅

Putting it in the middle like Za mu koyi sosai Hausa sounds wrong or at least very unnatural.

So:
[za mu] [koyi Hausa] [sosai]
= we will [learn Hausa] [very well]

Change za mu (“we will”) to the first person singular future form:

• A gaba zan koyi Hausa sosai.
  Later / In the future, I will learn Hausa very well.

Here zan is the fused form of za + ni (“I will”).

For the negative future, Hausa uses ba … ba around the za-phrase:

• A gaba ba za mu koyi Hausa sosai ba.
  Later, we will not learn Hausa very well.

Structure:

• ba
  • za mu koyi Hausa sosai
    • ba
      = “will not learn Hausa very well”

Approximate pronunciation (without tones):

• A – like a in about but shorter
• gaba – ga like ga in garden
  • ba like ba in bar → GA-ba
• za – za as in pizza’s “za”
• mu – moo
• koyi – roughly KO-yee (first syllable like co in cold)
• Hausa – HOW-sa (HOW + sa)
• sosai – SO-sai (SO like English so, sai like “sigh”)

So roughly: “A GA-ba za mu KO-yee HOW-sa SO-sigh.”