Question

Can you put el after un?

Answer 1

Not really because it wouldn’t make sense “un el libro…” right it sounds a little iffy but “un libro” sounds a little more educated

Answer 2

Answer: you could, but its unnecessary.

Step-by-step explanation:

For example, "un el lápiz" is the same thing as "un lápiz"

the "el" after "un" is not needed but you can do it.