English pronunciation is something which most students regard as an obstacle to learning the language, something which is illogical and seemingly designed to make their lives harder. And they're right. No, sorry; just kidding. It's difficult, true, but a better understanding of the ways in which Japanese pronunciation and English pronunciation differ can be not only interesting, but also helpful in improving your own pronunciation.
One of the problems is the use of "consonant clusters" (a consonant is the opposite of a vowel), such as the "str" in "strong", or the "nts" in "tents". They are particularly difficult for Japanese students because Japanese consists largely of "open syllables", i.e. syllables ending in vowels. If it's any consolation, native English speakers often have trouble with Japanese syllables such as "tsu" and "ryu".
English has many more "closed syllables" than Japanese does. This means that "tents" is only one syllable in English. "Hot" is also one syllable; the syllable is "closed" by the consonant "t". Japanese-style, of course, it becomes two syllables (or three, if you count the small "tsu") because the "t" becomes "to". The single closed syllable is turned into two open syllables.
Because of the way that English words link together when spoken at native speed, adding vowels to the end of syllables makes it harder to pronounce phrases and sentences naturally.
So, "Chaz and Dave" (a popular English musical twosome) might be pronounced "cha.zu a.n.do de.i.vu" (eight syllables) by a Japanese, when in fact it should sound more like "cha.zan.dayv" (only three syllables) - as if it were a single word.
It's therefore important to practice pronouncing consonant clusters, closed syllables and entire phrases - without inserting extra vowels. The best way to do this is to be aware of the theory (which I hope I've just helped to explain) and to copy native speakers wherever possible. Simply standing behind a pair of native English speakers on the Yamanote line and repeating everything they say is very effective... as long as they don't notice you...
Glossary - 言葉の意味
obstacle 障害
illogical 不合理な
just kidding ほんの冗談
a consonant cluster 子音結合群
a consonant 子音
a vowel 母音
an open syllable 開音節
a twosome ２人組
to insert 挿入する
a theory 理論
英語学習お役立ちグッズ
自分に合ったスクール選び 
英語力を活かして就職・転職
英字新聞・洋雑誌
海外留学・ワーホリ・旅行
