1. Essa televisão é mais cara. This is the comparative; a comparison between two things: i.e. This television is more expensive (than the other one) 2. Esse computador é o mais caro. This is the superlative, comparing one thing to many other things: i.e. This computer is the most expensive (of all the computers)

James is correct. I agree with him. “A menina é quem tem mais bolos” Something like: "The little girl is who has more cakes" or "The little girl is the person that have more cakes" . It means the same thing, but in this form with “é quem/é a pessoa” is a bit redundant, or intense if you wish. Same times it is used as a reference to the question - "Quem tem mais bolos?" Another thing In Portuguese “menina” is always a child. Girl is more like “moça” ,”garota (Brazil)”, “guria ” or ”rapariga” (this last only outside of Brazil, because here "rapariga" is related to promiscuity, a bad word). Update If you say "mais bolo" it mains that she has a big cake or more from the cake, not more cakes

3. A menina tem mais bolos. The girl has more cakes. But you don't have something to compare in this case. The girl has more cakes... ok, but more cakes than who? Than another girl? Than all other people? You just don't know. 4. A menina é quem tem mais bolos. The girl is who has more cakes. Here you know this girl is who has more cakes than everyone else in this context. So it could be considered superlative, such as James has said.

This television is more expensive. this computer is the most expensive. the girl is who has the more cake.