Korean words are written from left to right and words in a block-like shape. Syllables are organized into blocks of letters that have a beginning consonant, a middle vowel, and an optional third consonant (as well as occasionally a fourth consonant.)
A syllable block is composed of a minimum of two letters, at least one consonant and one vowel.
What if you only want a vowel? This rule still applies. Remember the character ㅇ? ㅇ is used as a placeholder for the consonant if you only want a vowel, because you must have a minimum of two letters per block.
For example, the vowel ㅓ is written as 어, ㅛ is written as 요, and so on.
You can have words that are C-V, C-V-C, and sometimes even C-V-C-C.
