Learn Hardcore Hausa: Idan muka yi aiki tsawon rana ba tare da hutu ba, gajiya tana ƙaruwa. - If we work all day without a break, tiredness increases.

In your sentence:
Idan muka yi aiki tsawon rana ba tare da hutu ba, gajiya tana ƙaruwa.
This is a general truth / rule. In English we’d usually say “If we work all day without a break, fatigue increases.”
But it also has a “whenever” feeling: “Whenever we work all day without a break, tiredness increases.”
If you want a clearer sense of “when (at the time that)”, Hausa can also use lokacin da:
- Lokacin da muka yi aiki tsawon rana ba tare da hutu ba, gajiya tana ƙaruwa.
  = When(ever) we work all day without a break, fatigue increases.

So idan on its own covers both if and whenever; context tells you which English word fits best.

Why is it muka yi and not mun yi or muna yin?

In Hausa, the mu- (we) pronoun changes shape depending on tense/aspect and clause type:

mun yi = we did (perfective, simple past)
muna yin = we are doing / we do (imperfective, ongoing or habitual)
muka yi = “we did / we do” in a subordinate or focused clause, often used:
- in relative clauses:
  - mutanen da muka gani – the people (that) we saw
- in conditionals and some “when/if” clauses.

In conditionals, Hausa very often uses muka yi:

Idan muka yi aiki tsawon rana…
Literally: If it is we who do work all day…
Functionally: If/when we work all day…

You could also hear:

Idan mun yi aiki tsawon rana…

The difference is subtle and speakers vary by region:

muka yi – often a bit more emphatic / focused on “we” or feels stylistically a bit more formal/standard in this type of conditional.
mun yi – still understandable; in some speech it’s common, but many grammars and textbooks prefer muka yi after idan for this general-conditional pattern.

muna yin would shift the meaning to “if we are (in the middle of) working…”, which is not the intended generic rule here.

What does aiki tsawon rana literally mean? Why tsawon?

Breakdown:

aiki – work
tsawon – length (of), lasting (for the duration of)
rana – day

So aiki tsawon rana is literally “work (for) the length of a day”, i.e. “work all day / work for the whole day.”

You could translate the phrase as:

work all day (long)
work for the entire day

Without tsawon, for example just aiki rana, that would not be idiomatic. tsawon is what gives the sense of duration “for the whole …”.

Other examples with tsawon:

Na jira tsawon awa biyu. – I waited for two hours (for the length of two hours).
Ya yi barci tsawon dare. – He slept all night.

How does ba tare da hutu ba mean “without a break”?

This phrase is based on two things:

tare da = together with, along with
The Hausa double negation pattern: ba … ba

So:

tare da hutu = together with rest / with a break
ba tare da hutu ba = not (together) with rest → without rest / without a break

Structure:

ba
- [phrase] + ba
  → makes the phrase negative.

More examples of this ba tare da … ba construction:

Na tafi ba tare da shi ba. – I went without him.
Ta yi magana ba tare da tunani ba. – She spoke without thinking.

So in your sentence:

…muka yi aiki tsawon rana ba tare da hutu ba…
= …we work all day without a break…

Could we just say babu hutu instead of ba tare da hutu ba?

babu hutu and ba tare da hutu ba are related in meaning but not interchangeable in all positions.

babu hutu = there is no rest / there is no break.
It’s a full clause (or at least behaves like one).
ba tare da hutu ba = without a break, a prepositional-like phrase that attaches to another verb phrase.

In your sentence, you want something that directly modifies how you are working:

muka yi aiki tsawon rana ba tare da hutu ba – we worked all day without rest. ✔

You could make a separate statement with babu hutu:

Muka yi aiki tsawon rana; babu hutu.
= We worked all day; there was no break.

So:

Use ba tare da X ba when you want “without X” as a modifier inside a bigger clause.
Use babu X when you want to say “there is no X / we had no X” as its own statement.

Why is it gajiya tana ƙaruwa and not gajiya yana ƙaruwa?

In Hausa, verbs agree with the gender of the subject (masculine vs feminine, grammatically). The subject here is:

gajiya = tiredness, fatigue

Gajiya is grammatically feminine, so we use the feminine subject marker:

tana = she/it (fem.) is …
yana = he/it (masc.) is …

So:

gajiya tana ƙaruwa – fatigue is increasing (correct)
gajiya yana ƙaruwa – ungrammatical, wrong gender.

Similarly:

ƙasa tana motsi. – The earth (land) is moving. (ƙasa = fem.)
girki ya ƙare. – The cooking is finished. (girki = masc.)

What exactly is ƙaruwa here? Why not just say gajiya tana ƙaru?

ƙaru is the verb “to increase.”
ƙaruwa is the verbal noun / gerund, roughly “increase / increasing.”

In Hausa, a common way to express ongoing / repeated / gradual change is:

X yana / tana [VERBAL NOUN]
literally: X is at/doing [increase / growth / movement…]

So:

gajiya tana ƙaruwa
= tiredness is in a state of increasing / tends to increase / keeps increasing.

You can say gajiya ta ƙaru:

gajiya ta ƙaru. – The fatigue increased / has increased. (a completed event)

But tana ƙaruwa is better here because the sentence expresses a general, ongoing tendency (a law-like statement), not a one-time event.

Could I also say gajiya ta ƙaru in this sentence? Would it change the meaning?

You could say:

Idan muka yi aiki tsawon rana ba tare da hutu ba, gajiya ta ƙaru.

This is understandable, but it sounds more like:

If we (ever) work all day without a break, then (at that point) the fatigue increases / has increased — more like a single change at some point.

With gajiya tana ƙaruwa, the idea is:

If we work all day without a break, fatigue keeps increasing / goes on rising.
→ more clearly ongoing / gradual and habitual.

So ta ƙaru = one completed increase,
tana ƙaruwa = increasing process or tendency.

Is the word order fixed? Can I say Gajiya tana ƙaruwa idan muka yi aiki tsawon rana ba tare da hutu ba?

Yes, you can switch the order:

Idan muka yi aiki tsawon rana ba tare da hutu ba, gajiya tana ƙaruwa.
Gajiya tana ƙaruwa idan muka yi aiki tsawon rana ba tare da hutu ba.

Both are correct and natural.

Starting with Idan… emphasizes the condition first: If/when we do this… then that happens.
Starting with Gajiya… emphasizes the result, and then adds when it happens.

Hausa allows this kind of reordering as long as the clauses themselves stay intact.

Outside of this conditional, what does muka yi aiki tsawon rana mean by itself?

On its own:

muka yi aiki tsawon rana is not a complete main-clause sentence in standard Hausa; muka is the form normally used in subordinate / relative / focused clauses.

As a main clause, you would normally say:

Mun yi aiki tsawon rana. – We worked all day.

You do see muka yi in main clauses in some narrative styles, often with an implied earlier context or contrast, but as a neutral, stand‑alone statement of fact, mun yi is the normal choice. Here, because it follows Idan, the muka form is exactly what you expect.