source:
AlexESLvid
http://www.engvid.com/
quiz:
http://www.engvid.com/5-native-englis...
#1 double negatives => avoid double negatives
#2 less vs. fewer
#3 (x) "I could care less." => (o) I couldn't care less.
#4 (x) "have went" => (o) have gone
#5 "is/are" and "was/were"