Dan also answered the question about “car black key” in his response, which I will paste here:
For the more objectionable [[N Adj] N] generator outputs like your “car black key”, they will only appear if you gave the generator the less likely MRS for “black car key” where “black” is modifying “car” instead of “key”. But if you want to protect yourself from these odd-sounding outputs in general, you could choose to block the two syntactic rules that license the [[N Adj] N] structures so the generator won’t use them. You do this by adding the following two lines to the end of the file erg/lkb/nogen-rules.set:
n-j_j-cpd_c
n-j_j-t-cpd_cThen once you recompile the grammar (for ACE) or reload it (for the LKB), you won’t see such outputs from the generator even if the MRS was not quite what you intended. for “black car key”. Note that these two rules are needed for parsing, to account for examples like the following from corpora, often but not always with a hyphen connecting the first noun and the following adjective:
pain-free existence
toll free number
traffic-free road
state subsidized company
user friendly software
avalanche-safe site
water-repellent coat
school-internal shuttle
cost-effective solution
tax deductible contribution
family friendly beach
drought tolerant plants
world-famous actor
color blind policy
power hungry politician
rock steady grip
coal-black night
care-free existence
fur-clad ancestorsWhile I think these N-Adj nouns should have a somewhat different semantics from the corresponding Adj+N ones, I so far have not landed on a satisfying MRS for them, so the MRSs are sadly still the same, which is why the N-Adj ones get generated from the Adj+N ones. Hence it seems okay for you to block the two rules above for the generator.