It's often hard for the opposite sex to read each other. Women seem too complex for men to comprehend, and men seem simple, unthinking, and unpredictable to women. If you know what you're looking for, however, there are always signs you can read in a person's behaviour. Add that to the fact that we live in an age or insecurity and anxiety, it can be hard to tell if when he says "I love you" he means it, or if he feels it even though he hasn't said it yet.
He Makes Sacrifices
When your partner is in love with you and committed to the relationship, he will do anything in his power to be with you. The sacrifices he makes can take form in many ways, he could move to be close to you or something as small as spending a romantic night with you instead of a night at the sports game.
There's a significant difference between listening and hearing. When a man is involved and interested in what he's hearing, or it's being said by someone he loves, he's more than likely to actually listen to what's being said. If he's in love with you, he will almost always pay this kind of loving attention to you.
He'll get jealous, there is definitely too much jealousy. That possessive and obsessive jealousy is something to look out for, but a man that loves you is going to have little flair ups of jealousy from time to time. It's actually really cute.
Your Always Beautiful to Him
In a relationship goes on, faults are noticed. To someone in love, those faults make them fall deeper in love as that show complexity and depth in the partner. A man in love will never find you not to be beautiful because he loves all of you, even the bits you don't love.
He Tries with Your Friends and family
To him the people that are important in your life are important to him too now. It's because he wants to fit into your life and wants to ever strengthen your other relationships if possible. He'll express this by showing keen interest in your friends and family.
A man in love is not afraid to show his emotional and venerable side to the person he is in love with. This will be very noticeable because usually a man will hide that side to the best of his abilities from everyone except maybe his mother.
When issues come up between you two a man in love is not trying to win the argument or relationship, he's genuinely worried about the threat to the relationship and that something may be hurting the person he loves. This lets him see and own up to his role in the issue.
As a man falls in love, he may actually become rather clingy. In new passionate relationships, this is often reciprocal and you two spend all your free time together. If it is unbalanced though it's not the end of the world because over time this 'loving clinginess' fades a bit.