True - but in a professional setting if you say "I'll call..." then that's it you're calling. You can't tag "..and raise you..." on the end - they would not accept the raise.
"I see your [bet] and raise you [x]" - would that be accepted?
Saying call and then adding a raise is similar to string betting, where you first put some chips to gauge your opponents reaction, and then put in some more. That's not allowed but so many beginners do it.
Some places may let you do it once, but by rule its not allowed in Casinos.