Used to form nouns from verbs of action.
Used to form a term denoting the ordinal numeral corresponding to the value, being a natural number, of a mathematical expression.
Used to form the ordinal numeral when the final term of the spelled number is not “first”, “second”, or “third”.
Forming adverbs denoting course or direction to, or motion or tendency toward, as in "backward", "toward", "forward", etc.
Forming adjectives, as in "a backward look", "the northward road", etc; used even by speakers who usually use -wards for adverbs.