When to use could and able to · exercise 1

My grandfather, who died last year, was an excellent musician. He ___ play the guitar very well.

When I was younger, I was useless at sport. I ___ throw or kick anything.

Your directions were very good so we ___ find the place without any problems.

There was nobody to disturb me so I ___ finish it quickly

When she was 15, she ___ run the 100 metres in only 11.25 seconds.

Before he got married my brother travelled a lot so, he ___ speak three languages.

Nobody understood what was happening so, the thief ___ escape.