googling :: "structure of the left" got me "structure of the left periphery" & the realization that linguists are jingoistic obfuscators who wouldn't know a clause if it jumped up and split their infinitives. honestly, they're worse than broken-down, self-exiled philosophers living in strange dirty smelly foreign cities.
but i guess they're not as bad as a 70% low-maintenance coalition suffering from a bad case of vote-moving issue.
or ... what gets moved to the left (adverbs?) periphery of a clause. something involving complementizers & all related (perhaps) to universal grammar, language acquisition & such. & something about the "cartographic approach" of (i think) the clause structure.
i guess it's how far left you can go (sentence-wise) & still retain the focus/force of meaning.