Imparfait (e.g.: je parlais)

Questions about the Imperfect

 Q: Why is it je suis né en novembre and NOT j'étais né en novembre

Remember, the imperfect describes a past situation, not a an event that happened once. Being born is an event that happened at a specific point in time; it is not a situation. It would, however, make sense to write: Quand je suis né, mon père travaillait à Montréal.

Q: Why is it j'ai été impressionné par son attitude and NOT j'étais impressionné par son attitude?

The imperfect would not be used here since we are describing an event that happened to the speaker. If you were to write j'étais impressionné, the implied meaning would be that you used to be impressed, but that you no longer are.

Q: Why is it il mangeait pendant le match and NOT il manger pendant le match?

The infinitive (manger) cannot follow a subject (like il). Since the meaning is "was eating", use the imperfect of manger here.