I have a small question.!

"you know" is an expression that's asking if a person understands or knows what you are trying to say or saying. It's usually put at the beginning or end of a statement.

Ex: Its like riding a bike you know?
Ex: You know its really windy today.

I hope this helps.

It's asking for understanding. Sort of like 分かった or ね
"It's odd, you know?" = "それ変, ね？”
Taya had a good explanation, too n_n

It's really sort of a slang, said without much thought, it just kind of slips out..you know? XD

Haha, I say this all the time, you know? It's sort of a way to know if the other person you are talking to understands what you're saying or wanting to say.

While "you know" does have the meaning previously stated, I believe what you are hearing is filler speech. Filler speech is something said to fill in the space when the speaker is forming the next thought in their head. Sometimes it's "you know" sometimes "like", or both together, but it could be anything. When words are used as filler, whatever meaning the words actually have can be ignored completely, because whoever is saying it is not actually trying to express any particular thought! Even though the words themselves have meaning, the speaker is not really telling you anything by saying them.

like the above person "you know" is filler speech for many people.
sometimes it gets changed just to "ya know" in more slang.

it is sort of a modern shorter version of the older "dont you know" -> "dontcha know"

in the west coast of the US, people will use the word "Like" a lot.
Ive noticed a lot of eastern people will prefer to use the word "right?"

depending on the region of the person, it will always change.

dont worry about it too much, it is a bad habit to learn ㅋㅋㅋ ;)

Yes I agree with anderyoung that it is a filler. Like "am", "actually", "usually", etc. Manny Pacquiao used to have a filler "you know" in all his answers in his interview but it was then corrected and gradually omitted.
Yes it is a bad habit as it destructs your listener.

you know you like a small girl, mhhhh, so ,you know "you know" is a spoken english,because english is a small language,is not the same as our east asian language and calture, american guy need a easy language and world ,do you know , girl????