final version

Can is used in the present and future. Could is the past tense of can. We use be able to to forma all the other tenses, for example, was/were able are the past of the previous form. Can is used in the present and future. Could is the past tense of can. We use be able to to form all the other tenses,. We use must when the speaker decides that something is necessary. We use have to when somebody else's made de decision. Ought and Should less emphatic. Need=necessary These structures suggests that an action did not happen because that isn't necessary Something is forbidden or you're not allowed to do it Positive, logical assumptions To express that something is likely to happen Can- general possiblility-Could/May/Might: something is likely to happen Asking, Giving and Refusing permission can-be allowed to: laws and regulations . Could: a permission in the past First set: to ask someone to do sth. Second set: to ask sth politely Modals to express the will or intention of doing sth Suggestions or instructions Must-Strong Advice- Should/ Ought-it is better Criticising someone else's actions