Sorry, I just realized you asked about "ish" - man, which is spelled איש. I saw you wrote יש, so I answered about that.
Anyway, both איש and גבר are words that mean "man". In plural, only גברים is used to mean "men". The word איש has an irregular plural אנשים, but it doesn't mean men, but rather "people".
I am fairly new to Duolingo. Who is Danny912421? Are you a teacher of hebrew or just an advanced hebrew student. I have used many Hebrew learning apps, and I am about to enter Adults Ulpan 4, also use the Pimsler Method for Hebrew. Having feed back from Danny is great, I look forword to seeing more feedback. שמואל Sanford Miller
I am glad you find it helpful. I am an advanced Hebrew student, who loves Hebrew, and being an English teacher by profession, I like helping others learn a language. Sometimes I feel I should tone it down and not answer so many questions, but a lot of questions are left unanswered for a very long time and people lose motivation that way. So I try and help them by addressing their doubts and questions. Good luck בהצלחה!