腐(くさ)っ()た() kusatta牛(ぎゅう)乳(にゅう) gyuunyuuは wa酸(す)っ()ぱ()い() suppai。 Spoiled milk is sour. Literal Rotten milk [topic-は] sour. 腐った (rotten) modifies 牛乳 (cow's milk) as a relative clause. 酸っぱい is an i-adjective meaning 'sour.' Simple and direct. foodrelative clause modifying a noun
腐(くさ)っ()た() kusatta牛(ぎゅう)乳(にゅう) gyuunyuuは wa酸(す)っ()ぱ()い() suppai。 Spoiled milk is sour. Literal Rotten milk [topic-は] sour. 腐った (rotten) modifies 牛乳 (cow's milk) as a relative clause. 酸っぱい is an i-adjective meaning 'sour.' Simple and direct. foodrelative clause modifying a noun