Some signs to look for to see if a man is in love is that he treats his partner with respect, he touches his partner in public and he states "I love you" to his partner. Other signs are that his partner is always on his mind, he compromises with his partner, he is willing to fight and apologize, and he talks about the future with his partner in it.
Signs of respect that show love include a man caring about the details of his partner's life and valuing his partners opinions. He also recognizes accomplishments and celebrates them with his partner.
When a man shows affection through public touch, he is proud of his connection. Another way that touch can indicate love is when he hugs and cuddles his partner without the expectation of sex. This shows that he is responding to the needs of his partner without simply considering what he wants.
A man may show his partner that he is thinking about her by sending silly texts during the day or by stating that songs remind him of his partner. It shows investment when he is thinking about his partner even when he is not with her.
Being willing to fight is another indicator of love, as it shows a man wants to understand the perspective of his partner. His desire to resolve conflict, and his willingness to say "I'm sorry," is an indicator of a strong relationship.