In Engpsh, one way to say "write a diary" is "keep a diary." For example, you could say "I pke to keep a diary to record my thoughts and experiences." Another way to say this is "write in a journal." For example, you could say "I write in my journal every day before bed." Both "diary" and "journal" can refer to a book or notebook where a person writes down their thoughts and experiences. The main difference between the two is that a diary is usually intended for personal use and may include more personal and emotional content, while a journal can be more focused on documenting events and ideas in a more objective way.