Ask him about how he perceives the relationship. Simply having a discussion with your partner can open doors to sharing personal feelings on the relationship and its future. Sometimes opening communication is all that is needed to resolve questions. Be tactful but direct, and tell your partner you'd like to know how he feels about the relationship and if he believes it will be long-term. With luck, a man who is satisfied just dating and not interested in settling down will be honest and say so.
Assess his habits. List the activities he does that involve you and those that do not. Events like family dinners, celebrations such as the birthdays of his siblings and get-togethers with his friends are obvious cues. If you are a regular attendant, he considers you someone important enough to involve with family and close friends. If not, this is a clear indication he is not looking for permanence or to integrate you into his inner circle.
Consider whether you have made any long-term plans. If you have been dating someone for a while and never talk about any future events that involve both of you, that's a sign you don't expect to be together for a long time. If his talk about future events is centered around himself, he probably does not intend to include you in his future.
Compare your interests. If you share common interests and pursue them together, this is an indication of compatibility. If not, and if he doesn't show willingness to become more involved in your interests, this can tell you his mind is not focused on sharing your life, likes and hobbies.
Pay attention to the activities you do together. Casual dating, like drinks in a bar, dinner and a movie or other impersonal social activities, does not fully constitute a serious shared relationship. If a man is interested in commitment activities, like taking you to his hangouts, having you come and watch his sports activities or going to the gym together, it indicates intimacy. The lack of this type of action means the relationship is likely casual or more physical than meaningful.
Monitor your conversations. If he is not interested in commitment, you may notice a lack of attention or concern. Someone interested in commitment will offer emotional support, listen and remember details. A man who doesn't have time for deeper conversations or seems disinterested when discussing your personal issues does not care about your well-being, and is not interested in a serious relationship.