First one is the old 'that vs which' - which I swear I'll never get my head around, no matter what clever ways I'm given to remember it. Should it be '... flowers tied to a tree that stands beside others.' or '... which stands beside others.' And secondly, what would be the clearest way to show / word the plural of X - as in when people write a line of kisses on a greeting card? eg: 'Only a line of exes / X's / Xs' It's for a poem so I need it to be instantly clear and obvious to the reader what the word is.