$11.$ more and more difficult
$12.$ more and more expensive
$13.$ more and more famous
$14.$ less and less
$15.$ more and more gently
$16.$ farther and farther
$17.$ less and less
$18.$ finer and finer
$19.$ more and more healthy
$20.$ busier and busier
NOTE: So sánh kép:
$1.$ Lũy tiến: càng ngày càng...
Sho S + be/ V + adj/ adv -er and adj/ adv -er
Ex: The climate is getting hotter and hotter
Long Adj/ Adv: S + be/ V + more and more + adj/adv
Ex: The environment is more and more polluted.
$2.$ Đồng tiến: càng... càng
Short Adj/ Adv: The adj/ adv -er + S$_{1}$ + V$_{1}$ , the more + N + S$_{2}$ + V$_{2}$
Ex: The older he is, the weaker he becomes.
Long Adj/ Adv: The more adj/ adv + S$_{1}$ + V$_{1}$ , the more + N + S$_{2}$ + V$_{2}$.
Ex: The more luxurious the car is, the more expensive it becomes.
$3.$ Càng càng với danh từ
Công thức: The more + N + S$_{1}$ + V$_{1}$ , the more + N + S$_{2}$ + V$_{2}$
Ex: The more books you read, the more knowledge you will get.
$4.$ Càng... càng với động từ:
Công thức: The more +S$_{1}$ + V$_{1}$ , the more + S$_{2}$ + V$_{2}$
Ex: The more he works, the more he earns.