A lot of Japanese can't distinguish pronunciation between "sea" and "she". Especially, "sea" is often pronounced as "she". So, when they want to say "Sit down.", they say "Shit down"! Awful!
There is a tongue twister "She sells seashells by the seashore. The shells that she sells are seashells I'm sure." This is our good practice sentence to make precise pronunciation of "sea" and "she".
Last Thursday, I attended the basic English pronunciation training class, after work. The class master gave a knack of tongue position, form of lips and breath. It is said that there are 43 sounds in English vowels and consonants. The number of common sounds in Japanese is only 5 to 6, meaning Japanese are not familiar with about 90% of English sounds.
I have subscribed "The Economist" for 3 years since my English teacher from UK recommended, however, I can hear the voice "Back to the basics" in my mind.