Learn to Play the Guitar Part 15
The D minor chord, at first glance, is simply the same as the D Major chord with the note on the first string moved down a half step. However, notice that the finger position for the D minor is quite different, in that the D Major has the second finger on the first string and the first on the third. The D Minor switches these finger positions.
Take some time practicing this chord and then practice switching between D Major and D Minor. After you can do this well, continue alternating between all the chords you have learned so far, calling out their names as you do so.