These participants were called "cases" in his original paper, but later came to be known as semantic roles or thematic relations, which are similar to theta roles in generative grammar.
1	These	this	DET	DT	Number=Plur|PronType=Dem	2	det	2:det	Discourse=elaboration-additional:43->42:0|Entity=(85-abstract-giv:act-cf1*-2-coref
2	participants	participant	NOUN	NNS	Number=Plur	4	nsubj:pass	4:nsubj:pass|6:nsubj:xsubj|15:nsubj:pass|18:nsubj:pass:xsubj	Entity=85)
3	were	be	AUX	VBD	Mood=Ind|Number=Plur|Person=3|Tense=Past|VerbForm=Fin	4	aux:pass	4:aux:pass	_
4	called	call	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	0	root	0:root	_
5	"	''	PUNCT	``	_	6	punct	6:punct	SpaceAfter=No|XML=<q>
6	cases	case	NOUN	NNS	Number=Plur	4	xcomp	4:xcomp	Entity=(90-abstract-new-cf5-1-sgl)|SpaceAfter=No
7	"	''	PUNCT	''	_	6	punct	6:punct	XML=</q>
8	in	in	ADP	IN	_	11	case	11:case	_
9	his	his	PRON	PRP$	Case=Gen|Gender=Masc|Number=Sing|Person=3|Poss=Yes|PronType=Prs	11	nmod:poss	11:nmod:poss	Entity=(80-abstract-giv:inact-cf3-3-coref(1-person-giv:inact-cf2-1-ana-Charles_J._Fillmore)
10	original	original	ADJ	JJ	Degree=Pos	11	amod	11:amod	_
11	paper	paper	NOUN	NN	Number=Sing	4	obl	4:obl:in	Entity=80)|SpaceAfter=No
12	,	,	PUNCT	,	_	15	punct	15:punct	_
13	but	but	CCONJ	CC	_	15	cc	15:cc	Discourse=adversative-contrast_m:44->43:0
14	later	late	ADV	RBR	Degree=Cmp	15	advmod	15:advmod	_
15	came	come	VERB	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	4	conj	4:conj:but	_
16	to	to	PART	TO	_	18	mark	18:mark	_
17	be	be	AUX	VB	VerbForm=Inf	18	aux:pass	18:aux:pass	_
18	known	know	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	15	xcomp	15:xcomp	_
19	as	as	ADP	IN	_	21	case	21:case	_
20	semantic	semantic	ADJ	JJ	Degree=Pos	21	amod	21:amod	Entity=(91-abstract-new-cf6-2-sgl|XML=<ref>
21	roles	role	NOUN	NNS	Number=Plur	18	obl	18:obl:as|28:nsubj	Entity=91)|XML=</ref>
22	or	or	CCONJ	CC	_	24	cc	24:cc	_
23	thematic	thematic	ADJ	JJ	Degree=Pos	24	amod	24:amod	Entity=(92-abstract-new-cf8-6-sgl|XML=<ref>
24	relations	relation	NOUN	NNS	Number=Plur	21	conj	18:obl:as|21:conj:or	SpaceAfter=No|XML=</ref>
25	,	,	PUNCT	,	_	28	punct	28:punct	_
26	which	which	PRON	WDT	PronType=Rel	28	nsubj	21:ref	Discourse=elaboration-attribute:45->44:0
27	are	be	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	28	cop	28:cop	_
28	similar	similar	ADJ	JJ	Degree=Pos	21	acl:relcl	21:acl:relcl	_
29	to	to	ADP	IN	_	31	case	31:case	_
30	theta	theta	NOUN	NN	Number=Sing	31	compound	31:compound	Entity=(93-abstract-new-cf7-2-sgl|XML=<ref>
31	roles	role	NOUN	NNS	Number=Plur	28	obl	28:obl:to	XML=</ref>
32	in	in	ADP	IN	_	34	case	34:case	_
33	generative	generative	ADJ	JJ	Degree=Pos	34	amod	34:amod	Entity=(57-abstract-giv:inact-cf4-2-coref|XML=<ref>
34	grammar	grammar	NOUN	NN	Number=Sing	31	nmod	31:nmod:in	Entity=57)93)92)|SpaceAfter=No|XML=</ref>
35	.	.	PUNCT	.	_	4	punct	4:punct	_
