Possible Duplicate:
Is it absolutely necessary to use “than” over “then” in a comparison?
Which sentence is grammatically correct?
"I have been here for less then six months."
or
"I have been here for less than six months."
Possible Duplicate:
Is it absolutely necessary to use “than” over “then” in a comparison?
Which sentence is grammatically correct?
"I have been here for less then six months."
or
"I have been here for less than six months."
You use 'than', not 'then' while comparing anything (not only time) in this fashion.
Eg.
"He is greater than 6 ft."
"He always scores better than you."
So,
"I have been here for less than six months."
is correct.