Subject	sail
Predicate	propel forward
Object	a boat
Modality	Modality Occurrences
Polarity	POSITIVE
Plausibility	0.8713
Neighborhood Sigma	0.8882
Local Sigma	1.0000
Example Sentences	Sentence Occurrences Source sails propel a boat forward what principle does a sail cause and object to move 1 Answers.com Questions