Преобразуйте в косвенную речь. kate said,"i will find the solution of this problem". nick said,"i learn english." nina said,"i wrote the letters". leo said,"i am reading the book now." anna said,"i have seen hin this morning."

В косвенной речи время, которое раньше было в прямой, опускается на одну ступень назад(настоящее становится и тд). Местоимения этот/эта/это превращаются в тот/та/то, сегодня становится вчера, вчера становится днем до этого(day before), а завтра становится следущим днем(next day)
Kate said that she would find the solution of that problem
Nick said that he learnt English
Nina said that he had written the letters
Leo said that he was readingthe book that moment
Anna said that she had seen him that morning