Pidgin Languages

I'm looking to make a pidgin trade language in my world, and I'm wondering
how to go about it.  There are three or four major languages in the area
where this would need to develop, none being ascendant over the others.
Does the pidgin language keep all features that the generating languages
have in common?  For example, all of the languages around this place inflect
their nouns for number.  Would the pidgin then do the same, as all of its
speakers have that concept in their own languages?

And for the phonology - would it make sense for the trade pidgin to have all
of the sounds that are found in all of the originating languages, or would
people be likely to adopt foreign sounds for a pidgin language?

Any information is appreciated.  Well, any useful information.

Joe

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