Like, dude! Whoa!
This sentence is linguistically incomprehensible (i.e. we can’t understand what is being discussed), but we understand the tone it implies: the speaker is clearly worked up about something. We don’t know whether the speaker is happy or angry, but if we heard this sentence while walking down the street, we’d all turn our heads and look to see what exciting thing is happening.
Incomprehensible sounds such as "Whoa!" are used in the above sentence – or words used out of context – have a grammatical term for them: interjections. Interjections are usually found at the beginning of the sentence, as we use the interjection either to get someone’s attention (“Hey! Watch out!”) or to give ourselves time to think about the real words (Oh, yum! This burnt, over-salted cake is utterly scrumptious!)