以下一段請俾意見:

You're invited to join the function for serving XXXX elderly center.
> If there is exactly one function going to be every held by your organization, it is fine to use "the." Otherwise, you should use "a."
> The elderly center is an object and cannot be served. Thus, the use of the verb "serving" is incorrect.

Out target is to provide XX service to 100 elderly people.
> Overall, this sentence is OK. It's cleaner if "100 elderly people" is replaced with "100 elders."
> I suggest that you combine this sentence with the previous one to provide a more comprehensive picture up front. For example: You are invited to join the function to serve 100 elders at the XXXX eldery center.

Our gathering time and time will be 9:00am at XXX MTR.
> The second instance of "time" is probably "location."
> There is no clear indication about the departure time from the MTR station to the elderly center.
> It is a good idea to be more specific about where to meet at an MTR station.

你究竟係唔識解定係想問人好唔好去參加啫？