He couldn't say how long it had been.
1	He	he	PRON	PERS-P3SG-NOM	Case=Nom|Gender=Masc|Number=Sing|Person=3|PronType=Prs	4	nsubj	_	_
2	could	could	AUX	PAST-AUX	VerbForm=Fin	4	aux	_	SpaceAfter=No
3	n't	not	PART	NEG	_	4	advmod	_	_
4	say	say	VERB	INF	VerbForm=Inf	0	root	_	_
5	how	how	ADV	WH	PronType=Int	6	advmod	_	_
6	long	long	ADV	_	Degree=Pos	9	advmod	_	_
7	it	it	PRON	PERS-SG	_	9	nsubj	_	_
8	had	have	AUX	PAST	Mood=Ind|Tense=Past|VerbForm=Fin	9	aux	_	_
9	been	be	AUX	PERF	Tense=Past|VerbForm=Part	4	ccomp	_	SpaceAfter=No
10	.	.	PUNCT	Period	_	4	punct	_	_
