Hata kama wewe ni Mwingereza lakini hapa umekosea. Huwezi kusema "...are commodities things that satisfy our wants directly"
"commodities things" is redundant. Commodities are things so you can not use those two words together as you suggested. I am practically a native speaker of English of TZ extraction and I am sure what you are suggesting here in a way of correcting that sentence is wrong.
Nashangaa sana wewe unajigamba kuwa ni Mwingereza halafu unatoa sahihisho potovu katika lugha yako.
It is not the way of I would have chosen to convey those thoughts. However, the grammar of the sentence was so bad that the whole thing lost its meaning and needed complete re-writing. I was trying to give the
intended sense of the original sentence (as I understood it),
without totally restructuring/re-writing it! The issue, as I said, has to do with the use of relative clauses - regardless of whether we are using commercial or other language.
There are innumerable examples of this structure with pronouns…
Are rivers, mountains and the like objects of direct moral concern? Or are
they things that, for their own sake,
we ought to treat one way rather than other?
I hear good and bad things about the jpod101; are the bad things just annoying and a few errors or
are they things that would severely throw one off one's game.
However, there are examples with nouns…
Schools are where children learn about what kind of behaviour reading is:
are books things that you get questioned about? Or things you read to yourself?
Are
trees things that block a clear view of you?
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Let me take an example from an academic text: ("Commodities, Commodity Fetishism, and Commodification" by Nicholas Sammond)...
"Commodities are things that are useful, or that satisfy human needs."
This is a statement from the text. If we make this into a question we get…
Are commodities things that are useful or satisfy human needs?
As I said, this structure has to do with the nature of defining relative clauses.
But you are right, even as an English teacher I still have things that I need to learn! Samahani sana kama nilijigamba!