This couldnâ€™t be farther from the truth. In reality it is necessary for a dialect to belong to a certain language for the word to even apply. The idea of a dialect means that it is a different way of speaking the same language. For example, American English is one way of speaking English while England English is another dialect of English.
To have a dream in which you are speaking in a different dialect means that you feel like you have not been getting yourself across well recently. Youâ€™ve tried your best to make sure that everyone is paying attention to you but you just havenâ€™t said anything of substance yet and havenâ€™t been able to get anyoneâ€™s real attention. If you have a dream where you are speaking in a different dialect it means that there is some specific message which you want to communicate to someone but it isnâ€™t working well because you canâ€™t figure out the best way to express yourself .Sometimes the best way to go about this is to simply just do as you are told and try to make the best out of the current situation.
A dialect can often be hard to translate even if you are a native speaker of the original language, but if you have a dream where you can understand exactly what someone with a different dialect is saying it means that you are good at relating to other people and probably at making friends too, congratulations.