1.     Schwa sound

https://www.youtube.com/watch?v=yWGCPXPkqG0&t=272s

I think almost 80% of unstressed vowels are pronounced with schwa sound in English

Ex)

Tunnel /ˈtʌn.əl/ Ipa symbol

https://dictionary.cambridge.org/us/dictionary/english/tunnel

Common mistakes: be careful do not pronounce word only based on spelling

Bank  /bæŋk/ æ graduation /ˌɡrædʒ.uˈeɪ.ʃən/ etc……..

kindly search keyword Schwa sound in Youtube

recording 10 words and send in teacher’s any available time