You love him. He shows every sign of loving you. He says he loves you! But so far, no proposal. Is there any way to get him to propose?
In one sense, no. One of the great truths of life is you can't make other people do things, and when it comes to marriage you probably do not want to. But, if the only thing holding him back is cluelessness, preoccupation, or nerves, there are a few things you can do to try to bring him up to speed. If that is all that is needed, then, yes, there are a few things you can do about getting him to propose.
First, ask yourself some questions: does he know you want to get married? For that matter, do you know, for sure, that you want to get married? Your own lack of commitment can set the pace, and more important if you are not ready you should listen to your instincts before rushing into things.
If you are ready, the first step is to let him know. There is not a chance you will get him to propose if he thinks you are not ready or willing. A basic "What do you want to do when you grow up?" or "Where do you see yourself in five years?" type of conversation is very useful in this case, and can be started over a burger and fries with no great agony on either side.
This kind of conversation is vital in any case: you want to learn if he hates the idea of kids, wants to live as a missionary in Africa, plans to work as a roadie with a rock band his entire adult life, etc. These are little things that may change your own idea of what you were hoping for in your relationship.
Likewise he needs to know you want twelve kids, six cats (one a St. Bernard), and a really great old farmhouse in Wisconsin. Or you are planning to be an astronaut. Or you've just been accepted to Harvard Law. Getting him to propose in some of these circumstances is possible -- but his own answers may make "yes" an answer you won't give.
Once you can say that he knows you are interested and that your plans match his, try asking him to help you make some future plans of your own. "Well, I got this great new job, and I won't turn that down, but I was worried what it would do to our relationship. How do you see this working out?" is a good example of a leading comment. You will not get him to propose if you don't open a few doors along the way for him.
Be ready to open the topic yourself. Perhaps, not an outright proposal, but at least a statement that you can't make your own plans if you don't know whether to factor a wedding in or not: are you planning a future for one, or for two?
If he seems unwilling to commit, then plan for one. Plan very openly for one, including a calm statement that you are thinking of seeing other people. Do not use it as a threat: that's a trap that can kill anything you share. But if he truly is not ready to commit, you must be ready to take care of your own future.
And planning for yourself, looking after yourself, is more likely to make you an attractive mate to bond with than being a patient, eternally waiting doormat. Getting him to propose is not worth the pain of the result if he was not willing, and mature enough to stand by it.
The main thing to remember is that you can't make an unwilling man propose, and the end would almost certainly be misery even if you did. Don't try to trap a man, don't try to corner him, don't try to get his friends to talk him over: stick to saying what you want, what you need, and what you hope for the future.
If that is not enough, then you don't want the grief of dealing with him. Honestly, you don't. Marriage to a half-hearted lover is grief from the first bars of the Wedding March, as unsatisfying as stale potato chips.