"We will not be able to cook stiff porridge if we don't try"
Translation:Tusipojaribu kupika ugali hatutaweza
Swahili is spoken just as english is. Hatutaweza means 'we will not be able' Tusipojaribu means 'if we do not try' Wherever the words are placed in the sentence is exactly where the translation should be. Only in very rare cases does one require to change the word placement.
it doesn't make sense without it. The '-po-' denotes if/when, depending on the sentence. Usually if it's negative (accompanied by the prefix '-si-', always present tense) it's 'if', e.g. 'usipofaulu...' = 'if you don't succeed...'. If it's positive (can be past, present or future) it's 'when': 'Alipoenda/anapoenda/atakapoenda' = 'when (s)he went/goes/will go'
The offered Swahili sentence says "If we don't try to cook stiff porridge we will not be able." which has a weird meaning compared to the basic English sentence: "We will not be able to cook stiff porridge if we don't try." Reported and asked for correction of the word order 22-Oct-2018
I see nothing wrong with a word-by-word translation here: Hatutaweza kupika ugali tusipojaribu or if you want to put the conditional phrase first: Tusipojaribu, hatutaweza kupika ugali. There is no reason I can see for jumbling the word order as the "correct answer" suggests, and in fact doing so changes the meaning slightly.
Duo can leave the jumbled version as the suggested correct answer if they wish, but the alternatives need to be accepted. Otherwise, it becomes another "copy and paste" exercise to get the "right" answer.