Un-happy, "un", you sounded like "an"
Often
Alter,"al"
outcome
along; "long",
expect: "e",
value: "a"
productive
menu" "e",
总之,我觉得元音是一个单词主干,一定要发准,发充分,。你发“e"时嘴容易张得太大,而发“a"时又显得不够大。还有就是“l"音,跟在元音之后时,虽然发音不必太重,但舌位一定要到位,否则听上去韵味不够,比如“all", "wall" 等等。写得匆忙,不周之处,望海涵。