'물냉면 하나요' = The order is one 물냉면. (하나 is vowel ending word, so the verb ending for 'is' will be '예요'='요' '물냉면 둘이요' = The order is two 물냉면. (둘 is a consonant ending word, so the verb ending for 'is' will be '이에요'='이요' ***These sentences are used when a customer responds to the server who is asking what to order or the server tells the cook what the customer ordered. For many occasions Koreans omit the subject, which causes some confusion to language learners. Happy practicing! =)