As Nick noted in comments, these are in fact two different people. The only thing that they have in common is being new, and involvement in this question.
However, your Spidey sense is keen when it comes to spotting this, the obvious signs are pretty much what we have here:
- Both new(ish) or unregistered accounts
- Sometimes older accounts with a new user making edits as if it were their own contribution
- Behavior from one indicates disenfranchisement from the other account
When you see this, you can point them here as Yannis suggests or casually ping a moderator or employee in chat. Only employees have the ability to merge accounts, but moderators can generally get a hold of us pretty quickly if you don't see one of us in a public room. You can also flag the post as 'other' and indicate that someone probably needs a merge, the moderators will send it to us if they agree.
Not being able to control your contributions can be a very frustrating experience so we really do appreciate a heads up (in whatever way is convenient for you) when you spot this so we can have a look.