Go through:
http://a4esl.org/q/h/9901/gc-connectives.html
http://a4esl.org/q/h/vm/conj02.html
http://a4esl.org/q/h/vm/conj01.html
http://a4esl.org/q/h/lb/anbutor.html
http://a4esl.org/q/j/vm/mc-andso.html