если бы он закончил проект, он бы п

если бы он закончил проект, он бы принял участие в конференции

Результаты (английский) 1:

If he had finished a project, he would have participated in the Conference

Результаты (английский) 2:

if he had finished the project, he would have taken part in the conference

Результаты (английский) 3:

if he has finished the project, he took part in the conference