The Importance of a Native
or highly proficient teacher.
Now just listening to Youtube videos is great for the ears, sort of, but unfortunately it doesn’t translate into proper pronunciation of English words.
Students really need to see the teacher’s mouth while learning and also have real time feedback and correction for the proper accent.
As Patricia Kuhl says in her TED talk video, babies watching videos of people speaking actually showed no effect at all compared to a real person.
From YouTube you get no feedback from teachers. When it comes to teachers who are not entirely proficient, or learnt English when older, they might have the problem of not hearing the mistakes in pronunciation when it happens and because they can’t hear they can't correct mispronunciation.
Especially in regards to the “R<->”L” and “B”<->”V” sounds. So accent is important but another thing to take into consideration is the grammar too.
Around the world English has become a creole language in many countries, where the natives of the country have taken a language such as English and changed it in a very short time, and now doesn’t resemble English grammatically at all.
If teachers from such countries try to teach formal English, there can be many pronunciation and grammatical mistakes.
I am not criticising very proficient nonnative teachers; I just want to highlight why I think it is important to learn from a native or very proficient teacher. Usually, they have attended international schools themselves.
Some examples of creole languages in English according to Wikipedia:
Jamaica : Jamaican Patois
Singapore : Singlish
Nigeria : Nigerian pidgin
Hawaii : Hawaiian creole
https://en.wikipedia.org/wiki/List_of_creole_languages
An indepth explanation of Creole