GRE® Question: toward vs. towards

[Laroche]

Hi,

I get confused with these two words "toward and towards" in that i dnt really knw when i use either one correctly. For example when i'm i supposed to use either in the ffg:

His attitude toward/(s) me;
Your attitude toward/(s) me;
My attitude toward/(s) you/him/them/it....etc

What i mean is do we use either of them in the situation of 1st,2nd, and 3rd person singular and also the case of 1st,2nd, and 3rd plural?

I hope i make myself explicit enough