Subject	christmas tree
Predicate	catch on
Object	fire
Modality	Modality Occurrences some[subj/real] 1
Polarity	POSITIVE
Plausibility	0.8870
Neighborhood Sigma	0.8870
Local Sigma	0.8870
Example Sentences	Sentence Occurrences Source christmas trees catch on fire 6 Google Autocomplete, Answers.com Questions real christmas trees catch on fire 1 Google Autocomplete