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I'm having some trouble understanding why は is used in the following response, instead of が. If someone could please help, I'd really appreciate it.
おさけ を のんだ こと が あります か / O sake o nonda koto ga arimasu ka? Have you ever tried sake?
いいえ, おさけ を のんだ こと は あり ません / iie, o sake o nonda koto wa arimasen No, I've never drunk sake.
Several people have pointed out that two previously similar questions answer my question, but to me they don't. I'm still confused as to why が cannot be used in the second sentence. Here, は is not used as contrastive, but neutral so I now understand why it is used based on Naruto's response. But I still don't understand why using が would be incorrect.
I have only learned hiragana and katakana so far, as I'm a newbie, so if responses could take that into account, I'd really appreciate it.