Do you mean like the particles and such? Or like...
Kore wa nan desu ka? (What is this?)
You know it's the end of the sentence because of the 'ka' in this case...You would understand, thanks to the ka, that they were asking you a question.
And as the other person mentioned, there are particles like 'wa'.
Watashi wa Tori desu (I am Tori).
Or particles like 'ga'.
Pizza ga suki desu (I like pizza).
As you learn it gets easier to figure out.
Hopefully this is what you meant. xD
Well, i'm not entirely sure, but if you hear japanese, and you read something like "watashi wa" it still sounds like one word, but you know it's not. It's probably something with the characters or something.