put the verbs in the past simple and the past continuous:
1) I ...(see) that Nancy ...(write) the letter
2) I ...(play) a new computer games,when you ...(phone)
3) When I ...(come) home my mum ...(cook) a tasty cake
4) It ...(be) rain,when he ...(get) up yesterdsy morning

1) I saw that Nancy was writing the letter 2) I was playing a new computer game, when you phoned. 3) When I came home my mum was cooking a tasty cake. 4) It was raining, when he got up yesterday morning