Complete the sentences with the correct forms of the verbs in the brackets. Use the past perfect continuous.
1. I did not go out last night because I (work) all day.
2. When I went to see Ms Winter, her secretary told me that she (speak) on the phone for two hours.
3. We (go) out together for two years before I met his family.
4. Around six o´clock he (take) the dog for a walk.