1. Conjunctions & Modal Verb
Coordinating Conjunctions
 and  or
 but  so
 for  yet
 nor
Subordinating Conjunctions
 after  than
 although  that
 as  though
 because  till
 before  until
 how  when
 if  where
 once  whether
 since  while
Modal Verbs
 can  should
 may  will
 might  would
 must