different is an adjective, communicate is a verb, difference and communication are nouns. They are different in part of speech. be + adjective : are + different Their differece is in part of speech. ronoun + noun : their + difference A tourist guide shall be able to communicate. to + verb Communication is a basic skill to be a tourist guide. subject (noun:communication) + predicate (be) + objective(noun: skill) hope that can give you a little bit of help. if your grammar is not good, i suggest you read some english text books. read loudly and recite sentences. you will find some language sense.