We have two basic ways of expressing simultaneous actions in Japanese, e.g. “I ate dinner while watching television”. Both translate as “while” in English, but the usage in Japanese is different.
|Eat dinner while watching television.|
|To go to sleep thinking about work.|
|To work your way through university.|
What about the order? Well, grammatically it doesn’t matter but there the final verb can be considered to be the “main” action.
|To eat dinner while watching television.|
|To watch television while eating dinner.|
|【Verb: Present Participle】
The kanji 間 we’ve seen used as a counter for time periods.
In this structure 間 is a noun which the present participle is modifying to express the time period while doing something.
|To refrain from drinking while pregnant.|
The critical difference between ながら and ～ている間に is that in the case of the former both actions will be performed by the speaker. On the other hand, ～ている間に is typically used when something else happens that is outside of your control while you are doing something.
|Yesterday while I was sleeping a burglar crept into my room and stole my wallet.|
|To get a phone call from a friend while watching television.|