Please capitalize where necessary: before you can open a hpl file, you'll need to figure out what kind of file the hpl file extension refers to.
A: Before you can open a HPL file, you'll need to figure out what kind of file the HPL file extension refers to.

Please capitalize where necessary: 1:5 the messengers returned to him, and he said to them, "why is it that you have returned?"
A: 1:5 The messengers returned to him, and he said to them, "Why is it that you have returned?"

Please capitalize where necessary: other games like amy's hospital
A: Other games like Amy's Hospital

Please capitalize where necessary: mobile phone operators should strengthen their focus on customer complaints
A:
Mobile phone operators should strengthen their focus on customer complaints