Vowel harmony is a rule in Turkish where suffixes added to words must match or "harmonize" with the last vowel sound of the word. There are two types of suffixes - "e-type" endings containing e and "i-type" endings containing i, each with multiple forms. When making nouns plural, suffixes of -ler or -lar are added depending on whether the last vowel is i, e, ö, ü or ı, e, o, u to follow the vowel harmony rule. Additionally, Turkish sometimes uses plural forms where English uses singular and vice versa, influenced by whether a number precedes the noun.

1. Vowel Harmony
When you agglutinate in Turkish, most of the ending usually have to rhyme, or harmonies, with
the word you’re adding them to. In order to be able to rhyme like this, the endings have a
number of different forms.
There are two types of ending:
• “e” endings which contain the letter e. They have two possible forms. For example, the
ending –le can be either –le or –la.
• “i” endings which contain the letter i. They have four possible forms. For example, the ending
–iyor can be –iyor, –ıyor, –üyor or –uyor.

2. Plurals
Words which name things (objects, ideas, people or places) are called nouns. In English, we make
nouns plural by adding an –s on the end. In Turkish, you add either –ler or –lar instead.
gün
akşam
gece
televizyon
günler
akşamlar
geceler
televizyonlar
Question: How do you decide whether to add –ler or –lar to a word?
Answer: Choose which one rhymes best with the last vowel in that word.
-ler harmonizes best with i, e, ö, ü
-lar harmonizes best with I, e, o, u
This is one of the rules of vowel harmony. The –ler ending is an “e-type” ending.

3. Plurals
Turkish sometimes uses plural forms where English uses singular forms, for example:
gün
iyi günler
şans
iyi şanslar!
day
good day
luck
good luck!
At other times, Turkish uses a singular form where English uses a plural! This occurs when there
is a number before the noun, for example:
iki gün
üç bilet
yüz gram
two days
three tickets
one hundred grammes