Thank you both for your answers.

N. You cannot mix these form up. You have to learn them. There are, however, a few verbs that can take either form. "Like" is one of them. I like doing. I like to do. I saw him drive. I saw him driving. There aren't a lot of these verbs, so the first rule generally applies.

In the first case, using the infinitive would be a big mistake.. this sentence rather calls for the subjunctive, "I suggest that you talk to her," because it implies a command. In the second case, either form works: "I don't like to waste my evenings" is as correct as "I don't like wasting my evenings." . As far as I know, this is the case for the verb "to like" (or to dislike, to hate, etc.), i.e. "I don't like to work at night," or "I don't like working at night." Though I reckon that the "-ing" form is used more often in the U.S. on the whole, both are correct. If you make a mistake in the first case, you might get some blank stares... If you use the infinitive in the second instance, nobody is likely to notice anything wrong.