They were
>(be) dead for a long time, but the company still produces books today.
Oni dalej nie zyja wiec tu trzeba czasu terazniejszego: They have been dead for a long time....
>Boon's son, Alan, once has sayed (say) that his father didn't think
>(not think) his books were serious.
Czas dobry, tylko sprawdz sobie jaka jest 3. forma czasownika "say". Nie jest to "sayed."
He .......?(think) that they were
>entertainment.
Ten sam czas co w poprzednim zdaniu.
It's certainly true that the books was (be) very
>popular for a long time and that they have entertained (entertain) a
>lot of people.
"was" to w tym zdaniu nigdy nie bedzie, bo to liczba pojedyncza, a "books" to liczba mnoga. Tutaj i tak potrzaba present perfect.
It's impossible to guess how many millions of readers
>has enjoyed (enjoy)
"readers" to liczba mnoga a "has enjoyed" to liczba pojedyncza.
But in 1998,
>eleven million British readers readed (read) a Mills & Boon.
Sprawdz jaki jest czas przeszly od "read". "readed" nie istnieje.
Someone
>have bought (buy) one every three seconds.
Tutaj dalej chyba mowimy o 1998 wiec potrzeba czasu przeszlego.