Can I use regular expressions with String.Replace in C#?

Answer to the question is NO - you cannot use regexp in string.Replace.

If you want to use a regular expression, you must use the Regex class, as everyone stated in their answers.

No, but you can use the Regex class.

Code to replace the whole word (rather than part of the word):

string s = "Go west Life is peaceful there";
s = Regex.Replace(s, @"\bwest\b", "something");