forward/forwards
backward/backwards
upward/upwards
downward/downwards
inward/inwards
outward/outwards
eastward/eastwards
westward/westwsrds
rightward/rightwards
leftward/leftwards
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Are both interchangable?
Which ones are from British English? Which ones are from American English?
1 answer
They are interchangeable. I think backward, inward, westward, etc., are more proper. Adding the "s" on the end is more colloquial, but by common usage, is quite acceptable. I don't know which is more American or British.