Past Perfect Progressive vs. Simple Past
I _____ (drink) coffee all morning. By lunchtime, I _____ (feel) really strange.
I had been drinking coffee all morning. By lunchtime, I felt really strange.
I _____ (wait) for hours, so I was really happy when the bus finally _____ (arrive).
I had been waiting for hours, so I was really happy when the bus finally arrived.
I _____ (see) John yesterday, but he _____ (run) so he was too tired to talk.
I saw John yesterday, but he had been running, so he was too tired to talk.
It _____ (rain) and the street _____ (be) covered with puddles.
It had been raining and the street was covered with puddles.
The boss _____ (talk) to clients on Skype for hours, so she _____ (want) a break.
The boss had been talking to clients on Skype for hours, so she wanted a break.
They _____ (study) all day, so when we _____ (meet), they were exhausted.
They had been studying all day, so when we met, they were exhausted.
When I _____ (arrive), it was clear that she _____ (work); there were papers and books all over her desk.
When I arrived, it was clear that she had been working; there were papers and books all over her desk.
Why _____ (be) the baby's face so dirty? He _____ (eat) chocolate.
Why was the baby's face so dirty? He had been eating chocolate.