Start thinking about the grammar rules.
1	Start	start	VERB	VB	Mood=Imp|Person=2|VerbForm=Fin	0	root	0:root	Discourse=joint-other_m:13->3:2
2	thinking	think	VERB	VBG	VerbForm=Ger	1	xcomp	1:xcomp	_
3	about	about	ADP	IN	_	6	case	6:case	_
4	the	the	DET	DT	Definite=Def|PronType=Art	6	det	6:det	Entity=(26-abstract-new-cf1-3-sgl
5	grammar	grammar	NOUN	NN	Number=Sing	6	compound	6:compound	Entity=(27-abstract-new-cf2-1-sgl)
6	rules	rule	NOUN	NNS	Number=Plur	2	obl	2:obl:about	Entity=26)|SpaceAfter=No
7	.	.	PUNCT	.	_	1	punct	1:punct	_
