It is a natural thing that when a person starts liking a girl and is planning to propose her, the behavior ultimately changes. So look up for this change in behavior in your boyfriend.
2. How His Parents are Treating You?
This is a vital sign of proposal. If a boy is going to propose you and he had a talk with his parents about you, they will treat you in a kind and polite manner, like their own daughter. If it is so, then be ready for a lovely marriage.
3.Change in Friends
There may be a slight change in the friends group of your boyfriend. If this is according to your likeness and unlikeness, surely he is valuing you more than his friends and the time is not far when he will value you above all as his spouse.