🚀 go-pugleaf

You may remember that Context Free Languages were discovered by a
Linguist, Noam Chomsky, not a computer scientist.  At the time (mid
1950's), there was great hope that a CFL, or at worst a CSL (context
sensitive language) could be found that would describe English, and
other such grammars developed for other natural languages.
Such efforts more or less met with utter and complete defeat in the late 
50's and 60's.  Indeed so much so that some people working in understanding
English (such at the folks at Yale), almost totally abandoned any
notion of syntax, and proceeded with just a semantic analysis of
utterances.  So I fear your quest will be a futile one; the best you
can hope for is a grammar for a rather stilted and minimal subset of 
English.

<sentence> ::= <subject> <verb> <object>
<subject> ::= I | teachers | policemen | the mob
<verb> ::= eat | love | detest 
<object> ::= mice | chocolate | teachers | little children