"several times" or "for several times"?

[Mehrgan]

Hi,
Does using "for" in such sentences make any difference? Is there any condition when "for" should be avoided?

"I've read that book (for) several times."
"I've been to Japan (for) twice."

Is there any rule for it? Thanks in advance.

 

[phrasemix]

Hi Mehrgan,
You shouldn't use "for" in either of these sentences you provided.