ystakes a valid vim motion or text object as first argument
ysiw": surround inner word with "
yss]: surround current line with ]
ys2aw*: add * around 2 words
vS": visually surround selected text with "
yswt: prompt & surround with a html tag
If a t or < is specified, Vim prompts for an HTML/XML tag to insert (also supports adding attributes)
yswf: prompt & surround with a function call
If a f is specified, Vim prompts for an function name to insert (use F to add space around ())
Takes 2 arguments a target to replace & a replacement character
cs]): change surrounding  with ()
cst<h3>: change surrounding html tag with h3
ds": delete surrounding "
dst: delete surrounding tag (HTML)
:helpg surroundfor more docs.