Forty NOT Fourty

·       FOUR = FOURTH

The word 'fourth' (with a u) relates to the number four.

FORTH = FORWARD

The word 'forth' shares the same first three letters as 'forward'.

·       FORTY NOT FOURTY

The word 'forty' (which obviously relates to the number four) is not spelt with a u.

 

This is a common spelling mistake, particularly in handwritten text.