These are modal auxiliary verbs. can could Must shall should will would 1. They go with another verb and and meaning. She can drive. I must get my hair cut. 2 There is no -s in the third person singular: He can dance very well. It will rain tomorrow. 3 There is no do/docs in the question. Can she sing? Shall we go? 4 There is no don't doesn't in the negative. I won't have a cup of tea, thank you. I can't speak French. 5 Most modal verbs refer to the present and future. Only can a past tense form, could I could swim when I was three.