You can usually think of "lo que" as "what" (or more literally "that which") when it is not at the beginning of a sentence. I don't understand what you are saying = no entiendo lo que dices. If you are starting a sentence with "what" then you need to use "que" (or cual). What are you saying = que dices?

Please take a look at the examples listed on this website and see if they help : http://www.studyspanish.com/lessons/relproelque.htm Buena suerte!

What I want to say is that=LO QUE quiero decir es que What do you want?=¿Qué es lo que quieres? What time is it?=¿Qué hora es?

Hola John, no se si te refieres al uso de LO QUE con valor intensificativo, por ejemplo, "Me molestó LO ALTA QUE estaba la música" = LO + ADJETIVO + QUE En el resto de usos creo que no hay demasiados problemas, pon ejemplos de tus dificultades y las analizamos. Saludos.