"You know" in spoken English [duplicate]

In most cases it's a space-filler with no meaning at all other than "er..."; or it means "well you do know, just give me a few moments to think of what it's called..."

"Where are you going?"
"I'm going to the, you know, shopping mall."

It's a lazy/terse form of the expression, "do you know what I mean" or "do you know what I'm saying" which is not only informal, but is specifically used directly with the usually singular or small-group audience to make sure someone is following along in a conversation.

Step on a crack, break your mother’s back

Two players pick cards from standard 52 card deck without replacement...

Recurrence and Fibonacci: $a_{n+1}=\frac {1+a_n}{2+a_n}$

Given $T \in L(X,Y)$, show the equivalence between: existence of $S$ such that $S(T(x))=x$, and $T$ being injective with $T(X)$ complemented in $Y$

Overlapping circles covering polygon

$ \int_0^\frac{\pi}{2}\ln^n\left(\tan(x)\right)\:dx$

Are $f$ satisfying $|f(y)| = |f(x+y) - f(x)|$ additive?

Exact expression of a trigonometric integral

If $A$ is a matrix such that $A^T = A^2$, what are eigenvalues of $A$?

Is there a reason the word "collection" is used in Heine-Borel theorem to describe an open covering instead of "set"?

Probability that there exists a person who will "only flip heads" or "only flip tails" in their lifetime?

Finding Taylor's series of the function: $\frac{e^{a \sin^{-1}x}}{\sqrt{1-x^2}}$