Roleset worsen.01 Verbnet Class: 1 "make or become worse":

Roles:

Arg0:agent (rarely occuring)


Arg1:thing getting worse


Arg2:instrument (preferable to agent)

Examples:

agentive but perhaps not grammatical (-)
John worsened his breath by chewing garlic-flavored gum.
Arg0:	John
REL:	worsened
Arg1:	his breath
Arg2-by:	chewing garlic-flavored gum




agentive? Instrumental? (-)
The buy-out effort also worsened already-strained relations between United's pilot and machinist unions.
Arg0:	The buy-out effort
ArgM-DIS:	also
REL:	worsened
Arg1:	already-strained relations between United's pilot and machinist unions




definitely instrumental (-)
Yesterday, Armstrong reported flat earnings for the third quarter and nine months, worsened *trace* by the stock dilution of an employee stock ownership plan adopted earlier this year.
REL:	worsened
Arg1:	*trace* -> flat earnings for the third quarter and nine months
Arg2-by:	the stock dilution of an employee stock ownership plan adopted earlier this year




ergative (-)
Gasoline margins may rebound this quarter, some industry officials say, but they believe chemical margins could worsen.
Arg1:	chemical margins
ArgM-MOD:	could
REL:	worsen