1. I hurt my finger while I was playing the guitar.
I was playing the guitar when I hurt my finger.
2. I was walking home when it started to rain.
While I was walking home, it started to snow.
3. She broke her leg while she was learning to ski.
She was learning to ski when she broke her leg.
4. He was making lunch when he suddenly felt ill.
As he was making lunch, he suddenly felt ill.
5. She was telling me about her party when she started to laugh loudly.
She started to laugh when she was telling me about her party.
6. I lost my wallet while I was shopping.
While I was shopping, I lost my wallet.
7. As the band were playing their first song, all the lights went out.
The band were playing their first song when all the lights went out.