2. They hint at you to make a move
Sometimes a friend is too shy to come right out and admit their true feelings for their friends. Sometimes they will wait for their friend to make the first move. Sometimes, after waiting a certain amount of time without success for their friend to make a move, they begin to grow impatient. At this point they will start to make subtle hints to their friend about the two of them together, and this is a clear sign that someone might have deep feelings for their friend.