Sorry, but I did *not* say "use English". I said "use ENGLISH" (ENGLISH being a dedicated data access language).
ENGLISH is the original Pick data query language, and is a very good NFNF query tool (It's also called ENGLISH because it is, actually, very similar to English!) For example
SELECT INVOICE WITH INVOICE.TOTAL EQ 1600 AND WHERE LINE.ITEM EQ 215
will select all invoices where the invoice value is 1600 and any individual line is 215.
SQL is *not* a "moderately straightforward mapping of the concepts of database retrieval to English" - no way would I describe it as "moderately straightforward", and it is very relational-oriented. Using it to query a non-relational database is *horrid*.