You should provide the context on what you mean to do when you want to change the horizontal and vertical alignment,
The UITextview has a container and a frame property that you can align with another UITextview/ Imageview, etc. The frame property has an origin and a size that you can modify to align your views.
The text within the UITextview has a property called the textalignment which you can set to NSTextAlignmentLeft, NSTextAlignmentJustified, As suggested, you may also adjust the content offset property of the container but I find that adjusting the frame is more straight forward.
