[Answer] Checkmate can be accomplished in four moves.

Step 1 : Introduction to the question "Checkmate can be accomplished in four moves."

...With the combination of a bishop and a queen, and if you move them at the right time, a four move mate is possible.

[Answer] You can checkmate your opponent with two knights and a king.

Step 1 : Introduction to the question "You can checkmate your opponent with two knights and a king."

...Again, this is very tricky, and is extremely hard to do. With some planning, a player can accomplish a checkmate.

[Answer] It is possible to be placed in checkmate with two bishops and a king.

Step 1 : Introduction to the question "It is possible to be placed in checkmate with two bishops and a king."

...It is very possible. It may be tricky, however if you get your opponent's king into a corner, it is possible to place him in checkmate.

[Answer] You can checkmate an opponent with two pawns and a king.

Step 1 : Introduction to the question "You can checkmate an opponent with two pawns and a king."

...It is tricky not to receive a draw, but if you play your cards right, you might receive a checkmate.