When we study English accent ourselves, we typically focus on study on consonant(子音) and vowl(母音). However, more important thing to learn seems to be how to pronunce letters which are not stress.
Let's take a look at an example
Most of the readers of this blog are very familiar with this word.
Please read this loud this once. I guess you said "プロナンシェ―ション" or something similar to this.
However, the IPA of this word is
The stress of this word is "ciAtion" part. Apart from the stress, let's look at first two syllables.
Here, you clearly see schwa ə sounds, instead of "o", "ou" or something else.
Therefore, vowls of "pronun" part may sound very similar. In practice, it can soud different because speaker's tongue and lip prepares for a coming consonant. Thefore, there are (probably) some variations among speakers accent how it sounds.
We should, however, keep in mind that the IPA of "pre nun" part is the same.
When it comes to long syllable words, this happens frequently. Here are some examples:
intonation: \ ˌin-tə-ˈnā-shən
characteristics: \ ˌker-ik-tə-ˈris-tik
There are some exeptions. But you see that there are many letters which are reduced to schwa sounds.
This is all for today.