In Exercise 3, beats 1 and 3 in the first measure are anticipated (syncopated) when they are tied to an off-beat eighth note preceding the beat. Care must be taken not to rush when playing longer eighth note patterns. In Exercise 4 and 5, patterns that anticipate (syncopate) the beat must be placed with precision so as not to rush the beat. It could be helpful to apply the triplitizing process to all of these exercises. You may also notice that you're playing in a new key.
Don't forget to observe all of the style markings when you click and imitate the new vocabulary.