${1.}$ That’s the architect who designed my house.
→ "who" thay thế cho "he" - N(người) + who/that + V
${2.}$ That’s the architect whose brother designed my house.
→ "Whose" thay thế cho "his" - whose + N
${3.}$ That’s the dog which bit me.
→ "which" thay thế cho "it" - N(vật) + which/that
${4.}$ That’s the dog that I kicked it.
→ giữa 2 chủ từ người và vật ta dùng "MĐQH" that
${5.}$ The boy who goes out with Jane is tall and lean.
→ "who" thay thế cho "he" - N(người) +who/that + V
${6.}$ The boy whom Jane goes out with is tall and lean.
→ "whom" thay thế cho "him" - N(người) +whom/that + S + V