He asked me what the matter was with the bike.
主句是He asked me,有了"asked"说明主句为一般过去式,What is the matter with the bike?是从句,宾语从句要求时态的呼应,主句为一般过去式从句应用过去的某一种适当时态,从句本来是一般现在式但因为主句是一般过去式所以应该用一般过去式,所以is应变成was,又因为宾语从句要求从句要用正常的陈述语序,（说白了就是主谓不用颠倒）所以要用 the matter was
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