Хееелп, помогите , очень прошу , вообще не понимаю , как преобразовывать слова эти

7 - couldn't

8 - later

9 - bought

10 - were sold

11 - first

12 - best

The Worst Musical Trio

George Enesco, the world-famous violinist, had a friend who wanted his son to become a musician. Enesco agreed to give lessons although the boy COULD NOT play a simple tune.

Three years LATER the boy's father insisted that he gave a public concert.

Although Enesco feared the result, he arranged a concert. However, nobody BOUGHT the tickets because the musician was unknown.

"Then you must accompany him on the piano," said the boy's father. This time all the tickets WERE SOLD.

Enesco was very nervous and asked for someone to turn his pages. In the audience there was Alfred Cortot, the brilliant pianist, and he was  the FIRST to make his way to the stage.

Next morning the music critic of 'Le Figaro' wrote, "The BEST violinist played the piano. The greatest pianist turned the pages. But the man who should have turned the pares played the violin."