The Alphabet | 1 - ālef
The consonant א is a glottal stop (marked /'/): a stop of the air flow, much like the initial sound in the word "about". It can only be pronounced when it is followed by a vowel.
While in spoken Hebrew, א is often silent, the written language reflects the principle that no Hebrew syllable can begin with a vowel. Thus if a word sounds to you like it starts with a vowel, it is likely that its first letter is א (or ע, as you will see later).
This rule also applies to words of foreign origin that start with a vowel.
For example:
אורגון (Oregon)
When א is the last letter of a word, it is always silent:
רופא (physician)
א is used as the vowel /a/, especially in words of foreign origin.
For example:
באלי (Bali)