情态动词的基本用法一. can(could)的用法1表示体力或脑力方面的能力，“能做，能够做”,be able to在表示能力时与can同义，但可用于各种时态，强调通过努力克服困难成功地做成某事，相当于managed to do 或 succeeded in doing。如 He can speak English. With the help of the firemen, the trapped people was able to leave the burning building. 2表示“请求. 3.表示许可”，4表示客观可能性“可能、会” 如：Everybody can make mistakes5表惊异、怀疑、不相信等态度（主要用于否定句、疑问句或感叹句中）How can you be so careless?6.表常有的行为与情形。“有时会，时而可能”He can be careless sometimes.7.can not .too/enough8.否定句中表有把握的推测9.can not b
