Mixed Tenses

Hallo! Ich bin Vikky und gehe in die 10. Klasse Realschule.

Könnt ihr mir bitte erklären warum man in diesen setzen ausgerechnet diese Zeiten hernimmt (die Fettgedruckten)? Bitte! Schreibe morgen Schulaufgabe und kommemit den Zeiten immer noch nicht klar!((((

He must be very hungry! He has eaten theree steaks and he still wants another one.

We are best friends. We have known each other since we were ten.

My sister has been learning French since she was seven.

When the Smiths finally arrived at the theatre, the play had already begun.

When the parents came home early from their holiday, their children had had a party in the living room.

Last summer Tom went to Florida. Until then he had never been to the United States.

Until last year Nicole had never eaten Christmas Pudding.