We have two sentences:
Tuo on salaattia.
Tuo on salaatti.
If I understand correctly, salaattiA refers to the green cabbage-like plant that we eat (also known as lettuce) and salaatti refers to the [final] dish which often contains lettuce, tomatoes, dressing, etc. Right? Wrong? Any comments?
I understood it differently. If I am not mistaken
Tuo on salaattia. refers to salad/lettuce in general. This is 'part of the' salad (that is existing in the world) This belongs to the category of salad.
Tuo on salaatti. This is the salad mixture I made. (This is all of it.) and actually when you want 'some' of it we probably have to add the 'a' again.
I checked sanakirja because I was incredibly confused and it said salaatti can mean either salad or lettuce. Not having that context before seeing salaattia being used to refer to lettuce was super confusing to me but I'm going to assume that it's from context you'll know which is being said.