Senses
唉 [response]
Used to answer a call or show that one has heard someone; yes; right.
唉 alas
Used to express a sigh or mild sadness
唉 [exclamation]
Used as a mild exclamation to show surprise or to get someone's attention.
唉 oh no
Used to express strong sentiment, sympathy, disappointment, or regret
唉 to admonish
(literary) To warn or admonish; used similarly to 誋
唉 yes
Used to express agreement, recognition, or approval