Question

está correta mr. dean's secretary ill yesterday, so he had to type the letters

Answer 1

Mr. Dean's secretary was ill yesterday, so he had to type the letters himself.

Answer 2

Não, o correto seria: Mr. Dean's secretary was ill yesterday, so he had to type the letters himself.

Estavam faltando as palavras was e himself. (Obs: corrigindo também algumas palavras que deveriam ser maiúsculas.)

Espero ter ajudado! Bons estudos!