1) Modal verbs

from: http://thecrazyteacher.altervista.org/category/can-i-help-you/verbs/


Here is an introduction to modal verbs:

http://esl.fis.edu/grammar/rules/modal.htm

Watch this video to revise the use of 'Must', 'Have to' and 'Should':





最后修改: 2016年02月8日 星期一 00:04