Complex sentence: It will pay $4 billion in cash, $12 billion in Facebook shares and an additional $3 billion in restricted stock units to be granted to WhatsApp's founders and employees that will vest over four years subsequent to closing.
Split into simpler sentences: It will pay $4 billion in cash and the remaining $12 billion in Facebook shares. The agreement also provides for an additional $3 billion in restricted stock units to be granted to WhatsApp's founders and employees that will vest over four years subsequent to closing.