"Just $29 per wash, tip is included" isn't great wording, certainly, but is there anything wrong with saying "tip's"?
I mean, certainly it's not formal, but then neither are pretty much all contractions in English. "Your tip's included in the bill" would sound fine, no?
Well yeah, that;s what I meant about it not being great either way - I was just disagreeing with parent comment about "tip's" not being a valid contraction.
"tip's" leaped out at me too - was just going to bitch about it here. I understand the "tip is" contraction. But it still sounds weird, still sounds like a plural. Un-contracted it would read "Just $29 per wash, tip is included". If that read "Just $29 per wash, THE tip is included" or "Just $29 per wash, THE tip's included" it wouldn't have made me cringe.
I mean, certainly it's not formal, but then neither are pretty much all contractions in English. "Your tip's included in the bill" would sound fine, no?