Many ESL students get in the habit of saying "one time", "one times", and "two times". "One times" is completely incorrect, and makes you sound like a complete babo!
While "One time" and "two times" is not incorrect, it's just much more natural to say: "once" or "twice" instead. Break this bad habit!
I have been to Busan one times before.
I brush my teeth two times a day.
I've seen him two times before.
I've been to Busan once before.
I brush my teeth twice a day.
I've seen him before twice.
1.) If we are describing situations or things that have happened several times, then we can say: "three times", "four times", "100 times", etc..
2.) We can say "thrice" which means three times. However, it is not commonly used and often referred to as being archaic.
1.) "It keep's me on my toes":This means that you are prepared, ready or alert. Think of a tennis player hopping back and fourth on his toes. The tennis player is ready and alert.
"I always do the daily crossword puzzle. It keeps me on my toes." (This implies doing the crossword puzzle keeps his mind sharp.)
2.) "A bitter pill (to swallow)": This means that a situation or information is unpleasant but must be accepted.
"Getting rejected from every university he applied to is a bitter pill to swallow, but he has to move on."