Слова указатели для past continious

Очень часто со временем Past Continuous используются следующие слова-указатели:

At five (six, seven) o\'clock - в пять (шесть, семь) часов;

when - когда;

while - в то время, пока;

all day long - весь день;

the whole morning - целое утро.

Например:

My parents were speaking by Skype at 4 am today.

She was watching TV while he read book. 

He was working the whole evening yesterday. 

They were playing on computer when the rain started.

I was cleaning my apartment all day long yesterday.