This sounds like what apologets of conversion therapy were saying, almost word to word. If it is learned, then it can be unlearned. And so many inhumane experiments shown that it is not the case. Many homosexual people in homophobic countries would like to "learn straight sexuality, even with an accent", but just can't. It is not how our body works - regardless of how much I will want to have sex with transman or with woman - my body will not answer, I will not be aroused. And same with the rest of homosexual people.

Language is learned by exposure and hearing of words, by repeating and hearing.

If sexuality was learned too, then everyone would be heterosexual, except kids in gay families. But kids in gay families are still often straight, while gays and lesbians are often appearing in straigh families, even in countries where gayness is banned. In USSR, in my childhood, word "homosexual" was nowhere to be found, nowhere shown that man can be with man or woman can be with woman, and yet there still were same amount of homosexual people as there nowadays. So this means it is innate, same as heterosexuality. Only bisexuals can "learn" or "fluid" their sexuality, and even then - not always (majority of bisexuals have heavy leaning towards one sex or another), and there ten times more bisexual people than homosexual people.