Verbs which are normally followed by the infinitive form:- afford / agree / appear / arrange / ask / attempt care / choose / claim / come / consent dare / decide / demand / deserve / determine elect / endeavour / expect fail / get / guarentee hate / help / hesitate / hope / hurry incline / intend / learn / long manage / mean / need offer / plan / prepare / pretend / promise refuse / resolve / say / seem tend / threaten / want / wish examples: • I can't afford to go to the pub. •He agreed to practise more. •You should learn to express yourself. •They managed to fix the problem.
People, achei vários sites, esse 1º tem a explicação bem clara e em Português. http://www.mundovestibular.com.br/articles/656/1/VERBOS-MODAIS-MODAL-VERBS-/Paacutegina1.html Esse tem muitos exercícios http://www.englishpage.com/modals/can.html Exercícios: http://a4esl.org/q/h/0101/ig-modals.html