of 后面接什么辅音时，f的发音省掉

of 后面接什么辅音时，f的发音省掉

以下是介系词of的发音的原文。当of后面为辅音字母开头的字时，of中的唇齿摩擦音f（实际上是v的发音）省去。
The word of is a preposition, and a function word. The vowel sound of that word is pronounced as schwa, and in this case we use the short u pronunciation, (short u), of.
Many times, however, we do more than use the weakest vowel sound in English to make the word of as small as possible. We also can take the consonant off the word. We just get rid of it; don't say it. Although of is spelled with an f, I hope you all are aware that it is pronounced with a v sound, of.
If the word that comes after the word of begins with a consonant sound, we can remove the v sound. If we do this we need to link the schwa sound into the following word, or it will sound strange.
Let's listen to some example sentences that use the word of whole, and reduce it to schwa. I am going to say the word of before the words the, my, cake, money, and Canada. All those words begin with consonants, so the word of can be reduced to just the schwa sound. Ready? Listen for the word of.
Incorrect spelling is only part of the problem.
That was: part of the problem
Repeat that after me: part of the problem
Two of my friends came along.
That was: two of my friends
Repeat that after me: two of my friends
I'd like another piece of cake.
That was: piece of cake
piece of cake
A million dollars is a lot of money.
That was: a lot of money
a lot of money
The United States is south of Canada.
That was: south of Canada
Repeat that after me: south of Canada
Now compare that to of linked to a word that begins with a vowel sound. In the following phrases, the v sound of the of should be said, and linked to the word that follows it. I'll say the word of before the words an, all, and each. Listen closely.
It only took part of an afternoon to make the cookies.
That was: part of an afternoon
Repeat that after me: part of an afternoon
She likes strawberries best of all.
That was: best of all
Repeat after me: best of all
I'll take two of each kind.
That was: two of each
Repeat that after me: two of each
Can you now hear the difference between the word being pronounced as of, and as just the schwa sound? Compare these two phrases:
part of the problem
part of an afternoon
Here those examples are again:
part of the problem
part of an afternoon
Linking the words together is what makes this work. Spoken English does not say each word separately, it transitions smoothly from one word to the next, often blending them together. It is a very important skill to have if you want to sound fluent in your own spoken English. To me, pronunciation practice really has nothing to do with accent reduction. Instead, it is about showing your listeners the level of English fluency you have by allowing your spoken word to match the fluency level of your written word.
希望我能帮助你解疑释惑。