in lesson 5.5 son las siete y media. translation- are seven thirty. why would they not say - es a las siete y media

I guess this is because it really means siete horas y media or seven hours and a half which is simply the way it is said in Spanish with the word 'horas' omitted. If it were one thirty, it would be 'es la una y media' because it is referring to one hour.

Hola a todos... Yes Phil, you are correct, we are talking about hours, in plural...so that is why : Son las siete y media....and not "es a las siete y media".... Saludos! buen dia!

It is in Spanish have 2 ways: Es la una....It is one; or Son las __...It is (for 2 -12). This ones are using to tell the time, but Es a las...It is at...is for saying that some activity is at that time. Example: Son las siete y media. It is seven thirty. ((Telling the time)) La clase es a las siete y media. The class is at seven thirty. ((telling at what time is the class))) I hope this help!!!!