2/3
Yes you can. There are many different ways of playing. Some people put a +4 card over a +2 card and some don't (I recommend to do it the +4 over +2 way)
2/3 or two thirds
two fifths
x^-2
2/8
1 over 2, 1/2, one half, a half, two fourths, 2/4 Save
In Uno, you can stack Draw 2 cards on top of each other, but you cannot stack Draw 4 cards. This means if a player plays a Draw 2 card, the next player can play another Draw 2 card to make the following player draw 4 cards. However, if a player plays a Draw 4 card, the next player cannot stack another Draw 4 card on top of it.
2/3 or .6 repeated.
In the game of Uno, you cannot play a Draw 2 card on a number 2 card. Draw 2 cards can only be played on matching colors or on top of another Draw 2 card. If you play a Draw 2 card, the next player must draw two cards and forfeit their turn.
They must draw 2 cards and miss a turn, however if they have another draw 2, they can put this ontop and make the next person draw 4!
YES
In Uno, you can be made to draw 2 cards multiple times if multiple players play "Draw 2" cards in succession. Each time a "Draw 2" card is played, the next player must draw 2 cards and forfeit their turn. If another player follows up with another "Draw 2," the total number of cards you must draw accumulates. There is no set limit to how many times this can happen, so theoretically, you could draw an unlimited number of cards in a single turn if the sequence continues.