Forward(s), Backward(s), Toward(s)

-ward(s)

Words like backward(s), forward(s), northward(s), outward(s) etc. can be used as adjectives or adverbs.

Adjectives

When they are used as adjectives, they do not have –s.

• African countries are backward in some ways.
• He was last seen driving in a northward direction.

Adverbs

When these words are adverbs, they can be used with or without –s.

• Why are you moving backward(s) and forward(s) ?
• If we keep going upward(s) , we will get to the top.

In figurative expressions such as look forward to, bring forward, put forward, the form without –s is always used.

• She put forward a very interesting suggestion.
• I look forward to hearing from you.