Answer:
I can be found in seconds, minutes and centuries, but not in days, years or decades.
What has 4 fingers and a thumb, but is not living?
Tickle with your fingers and a song it will sing. Be careful, though, you may break a string. What is it?
One more than a duet.
The more you look at it, The less you see.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?