Can we use past continuous tense to refer a past habit with adverbs of frequency words? For example:
He was going for a morning walk every day.
What is the difference between these two phrases?
- He was going for a morning walk every day.
- He would go for a morning walk every day.
They're all grammatical.
You could say
In those days, I was taking the train to work every day.
In those days, I took the train to work every day.
In those days, I would take the train to work every day.
The first, was taking, puts emphasis on the action as recurrent action, corroborating or reinforcing the meaning supplied by in those days and every day.
The second, took, relies solely primarily upon those temporal phrases for that meaning. (The simple present and simple past can refer to customary behavior.)
The third, would take, also corroborates and reinforces the idea of recurrent action, my then customary behavior.
The subtle difference between was taking and would take is that the continuous refers to the action as repeated or recurrent action, whereas would take refers to the single action as emblematic or representative of the customary behavior.
"He was going for a morning walk every day" is an unlikely form. The "used to" pattern would be preferred for this meaning: "He used to go for a morning walk every day". Simple past is also possible "He went for a walk every day". Your suggestion of "He would go..." is also possible but is quite formal, perhaps even literary in style.
Past continuous is used as "He was walking this morning between 8 and 9". The activity continues over a period in the past.
