"Do you speak Spanish" would come in two forms, depending on to whom you are speaking. For a formal tone, one would use "¿Habla usted español?". Informally, it would be "¿Hablas español?"
It depends on two things: 1) who statement is addressed to and the number and 2) the noun gender of the object.
In Spanish, there are different ways of saying 'you':
'tú' is the informal,...