As a copy editor, I’ve changed the word backwards to backward probably ten thousand times. Like the word towards, which I whined about in detail for other reasons, the difference between backward and backwards is likewise symbolized by the Atlantic Ocean—the line of demarcation between the two Englishes.
Don’t believe me? Okay. I have sources:
Backward means the opposite way, behind, in reverse, away from the front. Backward may also mean shy, not socially adept, or regressing instead of progressing. While technically backwards is interchangeable with backward, the overwhelmingly preferred spelling in the United States is backward, whether it is used as an adjective or an adverb.
The way I remember the difference is to think that Americans like shortcuts. For example, I’m willing to bet that we eat in our cars more than British people do. So think about how Americans like shortcuts, and think about how we lopped the s off backwards to make it shorter. In the US, we use the shorter word: backward.
Backward is an adjective that means regressive or underdeveloped. It is also a directional adverb in American English. In British English, it becomes backwards as a directional adverb, so keep your audience in mind when choosing one of these words.
And one of the very best sources, The New Fowler’s Modern English Usage Edited by R.W. Burchfield:
Backward(s) in most adverbial uses: backward and backwards are interchangeable, but usage varies subtly from person to person and from region to region. It is broadly true to say that in North America backward seems to be somewhat more usual than backwards and in Britain the other way round. As an adjective, the only form used is backward (without a backward glance).
So there you have it, my fellow Americans. It’s backward, leaving off the s for freedom!
Taking this a step farther, I also sometimes see backward used improperly, where the word back is actually the better choice.
If you’re standing facing north, say, and place your foot behind you, moving southward while still facing north, you are moving backward.
If you’re facing north and someone pushes you by placing his hands on your chest, causing you to fall in the direction of south, you have been pushed back, even if your face is still directed to the north.
Here are a few examples that might help:
Bronwyn, having pushed Galen back on his ass, walked away without a backward glance.
Galen, realizing Bronwyn would never change her backward ways, got up and went home without looking back.
“Let’s move the noon meeting back to two p.m.,” Bronwyn said into her communicator. “I think my relationship with Galen just took a big step backward.”
Fine distinction, yes, but no one ever said this was going to be easy!