Can I name a variable with the same name as a typedef'd structure name?

Question

Here is the structure declare code.

struct list_el {
    int val;
    struct list_el * next;
};

typedef struct list_el item;

And when I

Answer 1

you should use -Wshadow when you compile you code. Then, gcc will tell you where you are wrong. :-) like follows:
declaration of ‘item’ shadows a global declaration [-Wshadow]