Hatuwezi kutegua fumbo, achilia mbali swali la mtego.

Hatuwezi can be broken down like this:

• ha- = negative marker
• -tu- = we
• -wez- = root from kuweza, meaning be able / can
• -i = the final vowel used in this negative form

So hatuwezi means we cannot or we are not able to.

Compare:

• tunaweza = we can
• hatuwezi = we cannot

After kuweza (can / be able to), Swahili normally uses the following verb in the infinitive, which begins with ku-.

So:

• tunaweza kutegua = we can solve
• hatuwezi kutegua = we cannot solve

This is similar to English can solve, except Swahili uses the infinitive form more explicitly.

Yes. Kutegua literally has the idea of undoing, untying, or unraveling, and by extension it can mean:

• solve
• figure out
• decode
• untangle

That makes it a very natural verb for things like:

• fumbo = riddle / puzzle
• difficult questions
• mysteries or coded things

So in this sentence, kutegua fumbo is a very normal expression for solving a riddle.

Fumbo usually means riddle, puzzle, or sometimes mystery/enigma, depending on context.

Its plural is:

• fumbo = one riddle
• mafumbo = riddles

In everyday learning materials, fumbo is most often understood as riddle.

Achilia mbali is an idiomatic expression meaning something like:

• let alone
• much less
• never mind

It introduces something that is even harder, more extreme, or less likely than what came before.

So the logic is:

• We cannot do the first thing,
• let alone the second, more difficult thing.

That is exactly how it works in this sentence.

You should mostly treat it as a fixed idiomatic expression.

Literally, it comes from the idea of leave aside / set apart / put away, with:

• achilia = leave, let go
• mbali = far / aside

But in real usage, achilia mbali often functions as a set phrase meaning let alone.

So even if the literal meaning helps you remember it, the best way to learn it is as a whole chunk: achilia mbali.

Because the connector meaning of must agree with the first noun, not the second one.

Here:

• swali = question
• mtego = trap

So swali la mtego literally means question of a trap, i.e. trick question.

The key point is that swali belongs to a noun class that takes the associative marker la.

So:

• swali la mtego = trick question

This la is a grammar agreement form, not a separate word chosen freely like English of.

Mtego means trap or snare.

So swali la mtego is literally a trap question, which is why it means a trick question.

This is a nice example of how Swahili often builds meanings very transparently from smaller words.

Because Swahili, like English, often leaves out repeated material when it is already understood.

The full idea is:

• Hatuwezi kutegua fumbo, achilia mbali kutegua swali la mtego.

But repeating kutegua is unnecessary, so the shorter version sounds more natural:

• Hatuwezi kutegua fumbo, achilia mbali swali la mtego.

English does the same thing:

• We can’t solve a riddle, let alone a trick question.

We do not usually repeat solve there either.

Very often, yes.

It is especially common after something negative or difficult, because it sets up an even stronger point:

• Siwezi kukimbia kilomita moja, achilia mbali marathoni. = I can’t run one kilometer, let alone a marathon.

So in your sentence, it fits perfectly:

• first, something is already impossible
• then achilia mbali introduces something even more challenging

A careful syllable breakdown is:

• Ha-tu-we-zi
• ku-te-gu-a
• fum-bo
• a-chi-li-a
• mba-li
• swa-li
• la
• mte-go

A few pronunciation notes:

• sw in swali is pronounced together, like swah-
• mb in mbali is pronounced as a real consonant cluster, not with a silent b
• mt in mtego also stays clustered; Swahili allows that at the beginning of a syllable
• stress in Swahili is usually on the second-to-last syllable of each word:
  • ha-tu-WE-zi
  • ku-te-GU-a
  • FUM-bo
  • a-chi-LI-a
  • MBA-li
  • SWA-li
  • m-TE-go

Yes, depending on context, possible English translations include:

• trick question
• loaded question
• trap question

But trick question is the most natural general translation in many situations.

If you are learning the Swahili phrase itself, the important thing is that it refers to a question designed to catch someone out.