Пре­об­ра­зуй­те, если это не­об­хо­ди­мо, слово WRITE так, чтобы оно грам­ма­ти­че­ски со­от­вет­ство­ва­ло со­дер­жа­нию тек­ста.

So he often __________________ humorous letters to them. Very soon Chekhov got really interested in writing and sent some stories to publishers. Newspaper periodicals and literary journals started to publish his short stories.