1) A woman came into the room. Did you recognize her ?
=> Did you recognize the woman who came into the room ?
2) He passed the exam.
=> His friends congratulated him on his passing the exam.
3) They don't understand you, because you speak English unnaturally.
=> If you spoke English naturally, they’d understand you.
4) Though he didn't have enough money, he decided to hold a party.
=> Despite not having enough money, he decided to hold a party.
5)Her book was published last month. It became a best seller.
=> Her book which became a best seller was published last year.
6) The man is a famous actor. You met him at the party lastt night.
=> The man whom you met at the party last night is a famous actor.