Final answer:
To parenthesize the value of a variable called word, concatenate the '(' at the beginning and ')' at the end using the '+' operator, resulting in the expression '(' + word + ')'.
Step-by-step explanation:
To create a string expression that surrounds the value of a variable word with parentheses, you will typically concatenate the string '(' at the beginning and the string ')' at the end of the variable. In Python, for example, this can be achieved using the plus operator '+'. If the variable word contains the value 'sadly', then the expression would be:
'(' + word + ')'
When this expression is evaluated, if word = 'sadly', it would produce the string '(sadly)'.