. Used with 2 events that are occurring or existing at the same time, at the same time, in the past, according to this event requires significant Past Continuous Tense, for example.
. Use with two events that are happening. Or are in progress simultaneously at the same time as in the past, this event requires Past Continuous Tense both like.
. used with events 2 as is happening. Or going together at the same time in the past, according to this นัยน every event must be used Past Continuous Tense both pairs, such as