Upvote:5
The problem here is that it appears to UK immigration like you have been effectively living in the UK by taking multiple short term courses. This is explicitly not allowed, either on short term visas or on the terms of your visa-free access as a US citizen. Not only are you going to be disallowed from obtaining more short-term visas, you may be turned away at the border if you attempt to enter for any reason.
The only way round this is to spend a good amount of time outside the UK, to demonstrate that you are not attempting to live in the UK illegally. According to your revised history you spent almost two years continuously in the UK, but have been away from there for more than a year. The absence gives you reasonable hope that you might be granted another entry, but it is far from guaranteed. If you choose to apply again, make sure you leave reasonable gaps between visits. As a rule of thumb you should spend at least as much time outside the UK as in it, but even this does not guarantee there won't be problems. And remember that if have a record of being denied permission to enter this might well prevent you from studying at Saint Martins.
As @Traveller says, there are many reputable colleges in the US who will prepare you for admission to Central Saint Martins, and as you are a US citizen you do not need permission to attend. Take some courses from them instead. It will not be important to CSM that you take preparatory courses in the UK as opposed to elsewhere.
The question about the different passport is irrelevant. Restrictions apply to you, regardless of what passport you use.
Upvote:10
Rule #1 of visa applications is don't lie on visa applications. The UK short-term study visa application asks whether you have been granted any UK visas in the past ten years; so even if you apply using your Jordanian passport, you will still be required to include the details of your past short-term study visas.
If you falsely answer "no" to that question, and your deception is detected (due to a biometric match, most likely), then you can end up with a ten-year ban on receiving a UK visa. This will, I assure you, make it difficult to study at St. Martins.