He helps mom wash clothes.为什么wash不用第三人称单数?

He helps mom wash clothes.为什么wash不用第三人称单数? He ofthen helps her mom do the housework.（同义句）He often helps her mom do the housework.（同义句） He often____ her mom ____ the housework. He sometimes helps his mather wash the clothes.同义句转换 Peter often helps his mom m__breakfast. wash she help did her clothes mom Mom made me____(wash)the dishes wash she help did her clothes mom?连词成句 she usually helps mom do the wishing改为同意句she usually helps mom（）（）（） Tony often helps his mom do housework.改为同义句Tony often helps his mom（ ）（ ） she often helps her mother do some__(wash) Millie all helps her mother do some ______(wash) Lingling helps her mother wash clothes.(变为一般将来时) Sally often helps her mother wash the d---after dinner Kate usually helps her mother wash clothes的同义句 Kate usually helps her mother wash clothes的同义句 同义句转换 she ofen helps helps her mother wash clothes on sueday She often helps her mother ( to wash ) clothes还是用wash ( )YangLan is ______her mother ____the clothesA help ,wash B .helps ,washes c.helping,wash D.helping ,wash ing