1 Susan enjoys to have / have / having friends over to her house at the weekend.
2 He's really good at to play / play playing Dennis.
3 I think you should to get /et/getting a new phone. Yours is too small.
4 The students agreed to take / take / taking part in the project.
5 I'd really like to go / go oing to the concert on Saturday.
6 Joe migh to buy buy / buying that game if he finds a cheap one.