Complex sentence: Since its formation, the foundation has given more than $494 million to over 1,500 nonprofits and in 2010, Allen became a signatory of The Giving Pledge, promising to give at least half of his fortune to philanthropic causes.
Split into simpler sentences: Since its formation, the foundation has given more than $494 million to over 1,500 nonprofits. In 2010, Allen became a signatory of The Giving Pledge, promising to give at least half of his fortune to philanthropic causes.