just tell me that wat is the person trying to realy say for example my neclase cost me a arm and a leg wat the person trying to say is that the necklace was very expensive
I would say that "he's neat" means more than he's interesting. It means he is the kind of person I really like.
"What a trip" is also a little different, in my experience. It usually means that something was way better or weirder than you expected. For example, you might say this if someone you don't like at first turns out to be really wonderful. Most often it means that what happened was weird and unexpected. For example: What a trip! I flew back from the holiday, and a few days later I got a call from a cop asking if I was the guy that was playing with the Rubik's cube on the plane!! It turns out that the girl sitting next to me had disappeared!
"Did you see that Dude?" means that whatever the speaker is talking about was really wonderful or amazing. Dude is a "cool" way of referring to someone -- usually a male to a male.
If you say something "blew me away", you almost always mean that you were shocked in a good way. For example, winning that prize just blew me away. Other examples: That song was so "awesome" [really good] it blew me away; when she said she loved me it blew me away; etc.
Idiomatic expressions are statements in a language that cannot be literally translated into another language. Idioms are understood by most native speakers of a particular language. Idioms seem strange to non-native speakers who may translate the idiom literally.
Example: He's neat. Means "He's interesting."
not He's clean and tidy.
Blew me away is slang in the military for being killed.
in the drug counter culture it means really high. So, the idiomatic expression means that a person is very shocked.
What a trip! gets its meaning from the drug counter-culture. In the 1960s and early 1970s using acid was called a "trip". If something really interesting or exciting happens, then it is called "a trip".
There are many other idiomatic expressions in English.