She was hardworking. She got fired. --> ALTHOUGH
Although she was hardworking, she got fired.
He doesn't like celebrations. He really enjoyed his surprise party. --> HOWEVER
He doesn't like celebrations. However, he really enjoyed his surprise party.
He's not very tall, but he can jump high. --> ALTHOUGH
Although he's not very tall, he can jump high. OR He can jump high, although he's not very tall.