Essentials spawn item perm help

So I want to allow someone to only be able to spawn dirt for themselves, I use PermissionsEx and I've tried giving them all sorts of perms like:

Pex user abc123 add essentials.itemspawn.item-<dirt>
Pex user abc123 add essentials.itemspawn.item-

And none of them work, please help. Oh and also which command does this allow? /i or /give? I really need to find perms for /i...

Little help?

EDIT by Moderator: merged posts, please use the edit button instead of double posting.