The correct phrase is "I have begun." "Begun" is the past participle form of "begin."
Begun is correct.
I/you/we/they have begun. He/she/it has begun.
"I have not yet begun to fight!"
The population of Begun is 19,333.
Begun is the correct spelling.
Begun is the past participle of begin. Begin is an irregular verb.begin/began/begun
which year recycling begun in Germany
The present tense of begun is begin.
Iosif Begun was born in 1932.
Vladimir Begun died in 1989.
The Killing Had Begun was created in 1994.