Solution:
- David Silva is a football player who speaks Spanish.
- The park where you can go there at the weekend is beautiful.
- Last year which was a special year, a lot of important things happened that year.
- That's the teacher whose classes are brilliant.
- This is a great book which they want to translate into English.
- Piraha is an unusual language where only around 400 people speak it.
- George R.R. Martin, who is an American author, writes fantasy novels.
- We go to the cinema on Wednesdays, when there's a special price on Wednesdays.
Answer: who, where, which, whose, which, where, who, when.