In order to tell if your boyfriend is ready to settle down and get married, you need to talk to him about how he feels about a long term relationship. Start a conversation with him, and ask him where he would like to be in five years. If he appears uncomfortable, he might not be ready for marriage yet. A man can sense when his girlfriend is trying to talk to him about getting married, and if he isn’t ready yet, he will probably try to change the subject.
If he is ready for marriage, he will probably try to ask you how you feel about the subject. The only way to really know if he is ready or not is to talk to him. If you both have mutual friends, you can ask them to try to start a conversation with your partner about the issue to see how they feel about it. Maybe when you aren’t in the room, they will give a more honest answer about the subject.