"O chapéu custa menos do que o casaco."

Translation: The hat costs less than the coat.

[Frencesca]

o chapéu custa menos de que o casaco, Why is "de" wrong here?

[Paulenrique]

In comparison, we use "que" or "do que"

[Bonnie_B]

and this both means the same thing? Or are there different contexts in which you would use 'que' and 'do que' ?

[Paulenrique]

They mean the same ;)

[Jordansi]

Why is it used then

[Paulenrique]

It is optional, so both versions should be accepted.

[DavideTrapani]

Can I say "do casaco" without "que"?

[ThanKwee]

Paulenrique explained up above that you must say either "O chapéu custa menos que o casaco" or "O chapéu custa menos do que o casaco".