I am not certain what 'front vowel i' is meant to be, but I was taught to use 'I' not 'i' as is too often seen nowadays.
a unicorn, a uniform, a unicycle, a unit
The technical term for the vowel sound in the word "meal" - the "ea" sounding like the double e in "fee", for example, is a "close front unrounded vowel".
Tongue front
Generally, "a" is used in front of a consonant, and "an" is used in front of a vowel, or vowel-sound - a 'y' or a soft 'h'.
The word "back" has a short A vowel sound.
The boy rode on an elephant. ( "an" is used as "a" onlt when the word after it starts witha vowel )
You use the article "a" when your are using a word after it that does not start with a vowel (a e i o u) Example: Would you like A sock with your shoe? You use the article "an" When you are using a word after it that DOES start with a vowel Example: AN apple a day keeps the doctor away! Hope this helps! Truly yours, -Nathan
The word "back" has a short A vowel sound.
An is the indefinite article. It is used before words beginning with a vowel sound, for example an apple, an elder, an hour, another. It is shortened to a before words beginning with a consonant sound, for example a bat, a cat, a union, a European.Some words beginning with h may take the full form anwhen accented on the second or third syllable. For example we say a history but we may say an historian.Answerbefore a word beginning with a vowel, a-e-i-o-uAnswerUSUALLY, but not always, before a Vowel. Such as A Human Being, but An Explorer. A Tree but An Apple
A back vowel is a type of vowel sound that is produced with the back of the tongue positioned towards the back of the mouth. Examples of back vowels include "oo" as in "boot" and "aw" as in "caught." These vowels are typically characterized by a lower position of the tongue compared to front vowels.
The antonym for periphery using the vowel sound "or" could be center. The antonym using the vowel sound "ore" could be core.
An example of a vowel sound in the English language is the 'a' sound in words like "cat" or "bat." This sound is produced by a relatively open vocal tract with the tongue lowered and pushed towards the front of the mouth.