ne has always eluded me.
Write
Wrote
Written
What's the rule to this?
It's a tense thing. "write" is used for the simple present tense - "I write", "you write", etc.
"wrote" is the simple past tense - "I wrote", "you wrote", etc.
"written" is used mainly in the perfect tenses. "Perfect" means that it indicates an action that has reached its conclusion, and the related "perfect progressive" means the action is still going on. But each of these has three different variants, depending on whether we are talking about something in the past, the present, or the future:
Past Perfect: "I had written"
Past Perfect Progressive: "I had been writing"
Present Perfect: "I have written"
Present Perfect Progressive: "I have been writing"
Future Perfect: "I will have written"
Future Perfect Progressive: "I will have been writing"