这一切皆因在朗读时省略了第一个辅音的缘故，这样，单词就成了元音开头：

an [u] European country

an [i] historian

请网友仔细阅读老外下面的解答：

A Historical?  An Historical?

by Tina Blue

Once again Julie Lewis has asked a question that has led me to write an article for this website.

Here is her question:

Tina, can you clear up a little puzzle for me?

One of the members of a Webseed group I am in asked why British and Canadian people use "an" instead of "a" in front of certain words beginning with "h" (one of the Canadian members had written "an historical figure").

Oddly enough, last night I found myself automatically writing "an hysterical article" in my WOW! Newsletter, then corrected it when I read through it because I assumed that although I pronounce it that way, it shouldn't be written that way.

The person with the query asked if it was whether we pronounce the word following the "an" with a softer sound than Americans do, but I'm not sure.  We tend to half drop the aitch, if that means anything.  It seems too cumbersome to pronounce it in full.  

Someone else has just come back on this (another Canadian) saying she was taught that in some instances it is correct to use "an" and that it depends on the vowel following the aitch, but as it's a while since she was at school she doesn't know if this is still acceptable or not.  I certainly remember being taught at school that "an hotel" was the correct form and "a hotel" was wrong, but again I don't know whether this still stands or not.  I presume the same applies to "an herb", as the word is (apparently) meant to be pronounced without the aitch.  As far as "hotel" is concerned, I tend to include the aitch when I pronounce it (so I say "a hotel") and I never drop the aitch from "herb", because I always think it sounds terribly pretentious!

Can you possibly provide a definitive answer to this?  It's got me really puzzled now!  

As is usually the case, Julie's question highlights a difference between American and British usage--though even British usage is moving away from using an in such phrases.

In Sleeping Dogs Don't Lay,* Richard Lederer and Richard Dowis are quite dogmatic about whether or not one should use an before such words as historic and historical:

an historic (never)

"This is an historic occasion," intoned Senator Pfogbottom.

"I don't care to listen to this windbag," said the cynical reporter.  "I think I'll go to McDonald's for an hamburger."

. . . When the aitch (h) is silent, as in honor and hour, use the article  an.  When the aitch is pronounced, as in house, hamburger, history, and historical, use the article a. (33)

Well, sort of.  

There is a significant difference between multisyllabic words like hamburger, where the accent is on the first syllable, the one beginning with h, and historical, where the accent is not on the syllyble that begins with h.  

The problem is that the h is a bit of a wuss as a consonant.  When it occurs in an unaccented syllable and is followed by a vowel, it tends to soften to a vowel-like mushiness.  

Say these words out loud:  hot, hear, how, hurt, hateful, holiday.

Although the h in each of these words is followed by a vowel, the syllable the h + vowel combination occurs in is fully accented, and the h is aspirated (completely pronounced, in all its consonantal glory).  All of these words would, of course, be preceded by a, not an.

But now say these words out loud:  historian, historical, hysterical, heredity, habitual.

Do you notice how much less, well, pronounced the h is in these words?  Now, put a or an before each one (the adjectives should be paired with nouns so you can get the full effect):

a historian

an historian 

a historical reference 

an historical reference 

a historic occasion 

an historic occasion 

a hysterical display

an hysterical display 

a hereditary disease 

an hereditary disease 

a habitual liar 

an habitual liar

Notice that when you use a before the words, you fully aspirate the h, but when you use an, you do not--and the h sound very nearly disappears into the following vowel.

At one time, an was the preferred usage before an unaccented syllable beginning with h.  This is what the grammarian's grammarian, Henry Fowler, has to say on the subject:

. . . an was formerly used before an unaccented syllable beginning with h and is still often seen and heard (an historian, an hotel, an hysterical scene, an hereditary title, an habitual offender).  But now that the h in such words is pronounced, the distinction has become anomalous and will no doubt disappear in time.  Meantime, speakers who like to say an should not try to have it both ways by aspirating the h. (1)**

Since the early twentieth century, those unaccented h sounds have been more commonly pronounced than not, especially in American English.  But when Lederer and Dowis insist that an historical should never be used, they are promulgating a rule that is not yet carved in stone.

To many  Americans, an historical reference probably sounds pretentious and unlikely.  But to many of us who are middle-aged or older, that phrase sounds better (and is easier to pronounce) than a historical reference.  

Keep in mind, by the way, that in spoken language similar sounds tend to elide--i.e., to slur together into an indistinct vocal soup.  An unaccented h between two vowel sounds is notably unstable.  It will eventually collapse into its phonetic environment and become a vowel.

Widespread but half-baked literacy is probably responsible for the fact that the formerly unaspirated h in such phrases is now commonly pronounced, as is also the case with the word herb.  When people see such words spelled out, they tend to pronounce the silent or near-silent letters.  (Think of how often you have heard the word often mispronounced as of-ten, with the t, which should be silent, improperly articulated.)  

Similarly, when most people see the word historical, they fully pronounce the h, so an historical sounds somewhat inappropriate, while a historical sounds fine.  However, if you forget that you are looking at an h and simply pronounce the phrase, you will find that the h virtually disappears between the two vowels.

But wait a minute.

When the unaccented syllable beginning with an h occurs in a bisyllabic (two-syllable) word, something a bit different occurs.  Say an historical novel.  Now say an hotel.  Doesn't an hotel sound wrong, even though the h in hotel heads up an unaccented syllable?

There's a good reason for this.  

The strongest accent in a word is called a primary accent, but words of more than one syllable do not usually consist of a single accented syllable plus one or more completely unaccented syllables.  One or more of the word's other syllables will also receive some stress, though of a lesser sort.  

In the word historical, the first syllable is actually slightly stressed, though far less so than the second syllable, which carries the primary stress.  But in the word hotel, the first syllable, though less stressed than the second, is significantly more stressed than the first syllable in historical.  

In historical, the first syllable receives only tertiary (third-level) stress, whereas in hotel, the first syllable receives a secondary stress so strong that it is nearly equal to the primary stress on the second syllable.  For this reason, the h in a hotel is pronounced almost as fully as the h in a hot day.

So here's the general rule.

If you speak and write British English, you can probably keep using an before historical, hysterical, habitual, etc.  I doubt that you will be challenged by your own countrymen, and if Americans challenge you, just point out that British usage and American usage often differ.

If you are American, you probably should use a rather than an, even in a historic occasion or a historical reference.  Most of us are comfortable with a historic occasion, because the word historic has fewer syllables than historical, so the h is more fully pronounced.  But if, like me, you are old enough to find a historical reference a tad uncomfortable, then go ahead and say an historical reference.  

      And if you are challenged, simply trot out the explanation I have given you here, or better yet, send your challenger a link to this article.