question: unsure about which type of xys file you have? do you want to know exactly what it is, who created it, and how to open it?
Capitalize this past sentence correctly.
A: Unsure about which type of XYS file you have? Do you want to know exactly what it is, who created it, and how to open it?

question: this experience occurred on the tue 24 sep 2013 00:00
Capitalize this past sentence correctly.
A: This experience occurred on the Tue 24 Sep 2013 00:00

question: talk about cream that runs to the top.
Capitalize this past sentence correctly.
A: Talk about cream that runs to the top.