Oxford Dictionary says: "while-at the same time as sth else is happening eg: You can go swimming while I'm having lunch." so I am confused. Why doesn't Daddy Pig say "You go and dry yourselves while I'm polishing the car."?
Your question asks about the following forms:
- You do this while I do that.
- You do this while I’m doing that.
It’s arguable that the continuous form can apply to the situation where “that” is currently being performed whereas the base form can’t carry that sense. But both sentences can also idiomatically convey the same sense - an apportionment of roles where both “this” and “that” are only contemplated (not being performed) when the sentence is spoke.
The core difference is that the base form references the tasks in their entirety whereas the continuous form references the period/duration that “that” is being performed. Despite this notional difference, the use of “while” makes the pragmatics of the two sentences identical when “that” is not being performed at the time of utterance.
It seems to me that in option 1 neither event has happened as yet. But in option 2 you could be in the process of actually polishing the car while instructing the others. Option 1 (imo) sounds way more natural but both 1 and 2 are OK. Also in option 2 both the polishing and the drying can be done at some other time in the future, i.e, the drying can be done once the polishing starts!
Both forms reference concurrent actions. That is person A is doing one thing at the same time as person B is doing something else. However "You do A while I do B" suggests that the two actions are to be started simultaneously and completed in a similar time frame. In fact the suggestion is that A should be completed either at the same time as or, preferably a little before B. An example would be
You do your homework while I cook dinner.
In that case the parent is suggesting that the child should be able to complete the homework in time to eat the meal
However the continuous form suggests a more open-ended relationship. For example
You listen to some music while I cook dinner
suggests that activity A can be performed for an indefinite period and stopped when activity B is completed.
Also the Lockdown situation can result in this statement
You can't do your homework while I'm having a meeting, we only have one computer
which states that the activity B cannot take place at the same time as activity A regardless of the durations of the tasks. In this case the form
You can't do your homework while I have a meeting, we only have one computer
is not appropriate because the restriction applies regardless of the lengths of activities. As soon as the parental Zoom session ends the child can start her homework but both activities require the same resource and so are mutually exclusive