-ward vs. -wards
In American English, the preferred suffix is -ward—for example, westward, forward, backward, downward. Outside American English, -wards is preferred—so, westwards, forwards, backwards, and downwards. But it’s not a clean distinction, and both suffixes are used everywhere.
The -ward suffix may be placed at the end of any noun without requiring a hyphen. Spell check may catch words like cityward, mountainward, oceanward, or workward, but that shouldn’t stop us from using them.
Adjectives and adverbs
The backward spin of a number of black holes could create mysterious jets of plasma that control the fate of galaxies … [MSNBC]
Financial markets gyrated downward again Friday as investors turned skittish on banks … [Wall Street Journal]
Capitalization of north, south, west, and east
When used as nouns denoting specific regions, these words are capitalized—for example:
Threats of snow are shuttering schools across the South …
Abbas, who is traveling in the Far East and is due back in the West Bank on Monday, has not commented.
As adjectives, unless they’re parts of proper names (e.g. West Virginia, South Australia, West Bank), the words are not capitalized—for example:
The birds are usually found in Iceland, Greenland, western Russia and Canada.
Much of the northeastern United States is battling deep snows and blizzard conditions Wednesday … [VOA News]
Northerly, southerly, westerly, easterly
In many cases, constructions involving these adjectives can be shortened to one word—for example:
The vessel was reportedly heading in a northerly direction.
This sentence could be shortened to,
The vessel was reportedly heading north.
These -ly words are most applicable when something moves gradually in a general direction—for example:
… El Nino conditions in the Pacific Ocean have helped create the persistent, southerly storm track this winter …
Northernly, southernly, westernly, easternly
These are unnecessary words. Northerly, southerly, westerly, and easterly—without the n—are the standard words Similar words that combine directions—for example, northeasterly, southwesterly—also go without the n.