Tactics Traning #1: Puzzles for solving

Today we shall talk about some positions in training first we have this for White:
White to move, think for 3-5 minutes to find the best move for white.

The answer is Bd5!, cutting off the black queen from the c6 square. The rest I want yall to calculate it.

Second, this position is Black to move, this is easier so you only need 2-3 minutes to find the best move

The answer is simple AF! It's Qf1, threating Ne3 on the next move and a queen loss is inevitable.

Third one, a position arises from a very attacking style. Black to find the best move, you need 2-3 minutes to solve it
Yea, the answer is easy, Ne4, sacking the queen for a checkmate threat

And the last one which also has no solution from me, can you find it????
I'll make a hint here, it's about skewer!!!
See yall next time, bye ~~~~