Inflections of 'yes' (nnoun: Refers to person, place, thing, quality, etc.): nplplural noun: Noun always used in plural form--for example, "jeans," "scissors.": yeses
Inflections of 'yes' (v): (⇒ conjugate)
v 3rd person singular
v pres pverb, present participle: -ing verb used descriptively or to form progressive verb--for example, "a singing bird," "It is singing."
v pastverb, past simple: Past tense--for example, "He saw the man." "She laughed."
v past pverb, past participle: Verb form used descriptively or to form verbs--for example, "the locked door," "The door has been locked."
WordReference Collins English Usage © 2019
You use yes to agree with someone, to say that something is true, or to accept something.
‘We need to talk.’ – ‘Yes, you’re right.'
‘Is that true?’ – ‘Yes.’
‘Tea?’ – ‘Yes, thanks.’
Be careful
When someone asks a negative question, you must say yes if you want to give a positive answer. For example, if someone says ‘Aren’t you going out this evening?', you say ‘Yes, I am’. Don't say ‘No, I am’. Similarly, if someone says ‘Haven’t you met John?', you say, ‘Yes, I have’.
‘Haven’t you got any clothes with you?' – ‘Yes, in that suitcase.’
‘Didn’t you buy him a present?' – ‘Yes, I did.’
Be careful
Similarly, you say yes if you want to disagree with a negative statement. For example, if someone says ‘He doesn’t want to come', you can say ‘Yes, he does’. Don't say ‘No, he does’.
‘That isn’t true.' – ‘Oh yes, it is.’
'yes' also found in these entries:

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