Does "so long as" have the same meaning as "as long as"?

Rebecca

Excellent question. You are correct, both constructions are essentially idioms and interchangeable when used in the conditional meaning. "As long as" or "so long as" are used to mean 'provided that', 'providing that' or 'on condition that'. Ex: You are allowed to go as long as you let us know when you arrive. Ex: You can borrow the car so long as you don't drive too fast. However, it is key to remember that "as long as" can also be used in comparative expressions, where "so long as" cannot. Ex: This snake is as long as my arm. (Correct) Ex: This snake is so long as my arm. (Incorrect)