A good way for English learners to test their pronunciation is to use a voice dictation app on their phone. If the app understands every word you say, then your pronunciation is very good. However, if the app does not understand some words, then you know that you've identified some issues with your pronunciation. For example, in the first sentence above, the app said on the phone what I meant to say on their phone, this would indicate that I need to work on my final vowel signs. Try it out yourself and identify your key pronunciation errors.