How to use

Some masculine nouns have dictionary forms that end with -ок, -ец, -ёк, -он, -ен, etc. These endings consist of a vowel (о, е, or ё) followed by a consonant. Examples include:

• ок (e.g., подарок)
• ец (e.g., американец)
• ёк (e.g., кошелёк)
• он (e.g., сон)
• ень (e.g., день)

When forming the plural of these nouns, a phenomenon called the fleeting vowel occurs: the vowels о, е, or ё before the last consonant disappear.

For example:

• подарок → подарки
• американец → американцы

It's important to note that this rule has many exceptions, so it's best to check the plural form of each noun individually.

How to form

To form the plural of masculine nouns with fleeting vowels:

1. Identify the noun ending with a fleeting vowel (-ок, -ец, -ёк, -он, -ень, etc.). Check if the vowel is preceded by a single consonant. If the vowel comes after two consonants, the rule generally does not apply.
2. Remove the vowel before the final consonant in the stem.
3. Add the appropriate plural ending:
   • Use и if the final consonant is one of the 7-letter spelling rule consonants (г, к, х, ч, ж, ш, щ).
   • Use ы for other consonants.

For example: подарок → подарки

• Remove о → подарк
• Add и  → подарки

The same rules apply when declining these nouns in cases:

подарок →

• подарка (Genitive singular)
• подарку (Dative singular)
• подарком (Instrumental singular)
• подарке (Prepositional singular)