Чтобы поставить глагол в прошедшее время Past Simple нужно добавить в глаголу окончание -ed или посмотреть во 2 столбике таблицы неправильных глаголов. В отрицательных предложениях - didn't + глагол
1.The game was close, and any mistake could be costly 2.I knew that the game would be tight. 3.Both teams realize how important this game is. 4.This is what we were talking about. 5.I couldn't return your call yesterday, because I was too busy.