What’s in it for them? Objectively assessing the nature of any contact is notoriously hard to do, as well as often being quite dispiriting, but it nevertheless remains of the best ways to understand where communication is leading. In short, what is their intent? What do they stand to gain by talking/messaging with you?
No matter how the breakup panned out, communicating with an ex always carries a cost (usually the fear of further pain or confusion), and thus the benefit of communication must logically carry a stronger reward than whatever it is they stand to lose.
If the fear of confusion or the guilt of leading you on weighed more than the benefits associated with talking to you, they would avoid doing so. So, if communication remains, it begs the question. What are they getting out of it?
Attempting to keep their options open
An ex who is attempting to keep their options open will attempt to stall and waste time in an effort to decide which grass is greener, yours or the rosy new dawn they envisioned (but hasn’t quite panned out they way they wanted).
While communication may be somewhat constant, it is usually a frustrating much a-do about nothing where the ex in question will attempt to offer an emotional lifeline, but shy away from any form of real, tangible commitment.
Attempting to alleviate guilt
Sometimes the line between altruism and egotism can blur. No matter how self-centered the guilt is, and it can vary from genuinely caring about your pain, to attempting to coax lingering feelings of self-centered guilt (and occasionally both at once).
Either way, the discrepancy in intent will lead to resentment, because pandering to guilt will only materialize false hope in the mind of the dumpee. I would personally prefer being given the silent treatment because at the very least it is an answer, rather than drown in waves of over-analysis.
Exes attempting to alleviate guilt will often engage in sporadic heartfelt contact, but as is the case with the aforementioned point on keeping their options open, they will flip-flop or fully retreat at any mention of constancy or commitment.
Attempting to reconcile
This is the least common end-result of post-breakup communication, but the world all around is proof that it happens alarmingly frequently (I say alarmingly because research suggests that giving it another shot is almost always a short-term fiasco).
My probably misplaced pessimism aside, deciphering intent here is a little easier than the other two examples, if only because relationship building is all about consistency, which should be reflected in both the tone, and the nature of communication. If communication slowly escalates, and small consistent steps are mutually taken to water the budding flower of romance, things are looking up with regards to reconciliation.
I would nevertheless urge caution, because separation will often catalyze insecurity and have exes who made the decision to breakup temporarily forget why they did so. Unless steps are taken to address the issues that led to a parting of ways, it will all be a case of history repeating.
Who’s Doing The Initiating?
Another indicator of intent to consider is the degree to which an ex is willing to initiate contact. If all they are realistically doing is politely replying to your attempts at contact, I believe it is fair to say you are positioning yourself on an emotional precipice. Unless, of course, that is a character trait they have always had (even when you were dating).
If their attempts at contact are sporadic at best, try to match their rate of contact and see where it leads. If contact dwindles to nothing, or ends entirely, it might not be a case of them leading you on, but the all too common case of our own minds leading ourselves on (and it pains me to lay this point out this brutally, but nevertheless I feel it has to be said).
While swift replies to your attempts are contact are a sign that they continue to respect you. They are not by themselves signs that reconciliation is at hand. If reconciliation, rather than friendship, is what you are after, I would personally urge you to let the contact hammer fall and witness where it lands. Give them the space to initiate at their own rate of comfort, and que sera, sera.