How exactly do you do it? I know when you write in third person each character has their "syntax." So how do you change between syntax in a chapter? Do you just talk different for each paragraph when it involves a characters thoughts, or what?
I think that you're a little confused about third person omniscient.
When you're using third person omniscient you're not actually talking as if you are every character, you are talking as if you are a God looking over the world and describing their actions. You talk about every character the same way, and only keep to their syntax when they are talking or thinking. The narration is you, the author, speaking, not the character.