1. simple
   1. simple future at one particular time in the future
      1. note
         1. future time
         2. will / be going to
            1. prediction: will / be going to
            2. prior plan: be going to
            3. willingness; will
         3. when + S + V
            1. expressing the future in time clauses
   2. simple present alway, usually, habitually
      1. general statement of fact and timeless truths
      2. habitual or everyday activities
   3. simple past at one particular time in the past
      1. - began and ended at a particular time in the past
2. progressive be + V-ing
   1. future pro. will + be + V-ing be going to + be + V-ing
      1. in progress at a time in the future
   2. present pro. in progress at the present time
      1. in progress at the moment of speaking
   3. past pro. in progress at a particular time in the past
      1. one action began ealier and was in progress when the other action occurred
   4. note
      1. stative verbs
         1. usually not used in progressive tenses
      2. am / is / are being + adjective
         1. stative meaning
         2. progressive meaning – behavior
      3. raise / rise, det / sit / lay / lie
         1. raise, set, lay + an object : transitive verbs
         2. rise, sit, lie: intransitive verbs
      4. hai hành động cùng xảy ra, cùng kéo dài: dùng 2 thì tiếp diễn
      5. always
         1. in present time, always: habitual or everyday activities
         2. be + always + V-ing: complain (annoyance, anger…)
         3. always / forever / constantly
      6. place
         1. be + place + V-ing: focus on place not action
3. perfect have + PP
   1. future per. finished before another time in the future
   2. present per. finished somtime before now
      1. before now, at an unspecified time in the past
      2. repetition of an activity before now
      3. ever / never / already / yet / still / just / so far
      4. since / for
         1. began in the past and continues to the present
   3. past per. finished before another time in the past
      1. completed before another activity or time in the past
4. perfect progressive have + been + V-ing
   1. future per. pro. before another event in the future, how long?
      1. duration / inprogress before another time or event in the future
   2. present per. pro. before now, up to now, how long?
      1. duration / began in the past and continues to the present
      2. a genaral activity in progress recently, lately
      3. for / since / all day / all week / all morning
   3. past per. pro. before another event in the past, how long?
      1. duration / in progress before another activity or time in the past
      2. in progress close in time to another activity or time in the past