SIMPLE TENSES
      A. Simple present = base form: I work.  OR base form + -s:  He work s . She work s . It work s . OR base form + -es : I watch / she watch es ; I study / he stud ies   1. A  general truth.               The sky is blue.   2. A typical activity.               I always brush after I eat.               Bob watches TV every night.               Sara works 5 days a week.   3. A statement of something existing at the time of speaking.               I hear the train coming.                I smell smoke.   4. A scheduled event or activity.               My plane leaves at 8:30  tomorrow.      B. Simple past  = base form + -ed for regular  verbs : I worked yesterday. The simple past for irregular  verbs varies : He ate lunch at noon . (irregular verb)   1. An activity begun and completed at a particular time in the past.               I went to work yesterday morning.   2. Commonly used with “after” and “before” clauses.               After Bob ate dinner, he drove to CEC.               Th...