like 后面可以用 -ing 形式，也可以用 to 加动词原形。I like swimming. 和 I like to swim. 都是正确的英语。
like + -ing
I like swimming at Farrisen Gym.
I like to swim before work.
Mateo likes reading in the park.
Not "I like swim." — say "I like swimming.". 动词原形不能直接跟在 like 后面。要用 -ing 形式，或者在动词前面加 to。
试一试: Yasmin: What do you do on a free morning? Lars: I like ___ on the trail. 补全 Lars 说的话。 (running / run / to running) 答案: running — -ing 形式直接跟在 like 后面，所以是 running。动词原形 run 不能单独放在这里；to 后面的动词要用原形，所以 to running 在这里也不行。
enjoy + -ing
enjoy 后面可以直接接东西，比如 I enjoy my class。如果 enjoy 后面接的是动词，就要用 -ing 形式：要说 I enjoy swimming，不能说 I enjoy to swim。
Camila enjoys running on the trail.
We enjoy playing games after dinner.
Lars enjoys reading in the evening.
Not "I enjoy to read in the evening." — say "I enjoy reading in the evening.". enjoy 后面的动词要加 -ing。那里不能用 to 加动词原形。
试一试: Lars: Is the new book good? Sofia: Very good. I enjoy ___ in bed. 补全 Sofia 说的话。 (to read / reading / read) 答案: reading — enjoy 后面接 -ing 形式，所以是 reading。to read 是跟在 like 后面的用法，不能跟在 enjoy 后面；动词原形 read 也不能单独放在那里。
swim 变 swimming，run 变 running
有些短动词在加 -ing 之前，要把最后一个字母双写。
swim becomes swimming
run becomes running
read becomes reading, with no double letter
试一试: Wei: What do you do in the kitchen at Farville? Camila: I like ___ the vegetables. 补全 Camila 说的话。 (cuting / cut / cutting) 答案: cutting — cut 加词尾之前要双写最后一个字母，所以是 cutting，有两个 t。cuting 只有一个 t；动词原形 cut 也不能直接跟在 like 后面。
want / need + to + 动词
want 和 need 后面要接 to 再加动词原形：I want to swim. 和 I need to go.
I want to play basketball today.
Mei needs to go home now.
Do you want to watch the film?
Not "I want swim this evening." — say "I want to swim this evening.". want 后面可以直接接东西，比如 I want a ticket，但接动词时前面要加 to。
试一试: Diego: The class starts in five minutes. Amina: I know. I need ___ my keys first. 补全 Amina 说的话。 (find / to find / finding) 答案: to find — need 后面接 to 再加动词原形，所以是 to find。动词原形 find 不能直接跟在 need 后面，finding 是跟在 enjoy 后面的用法。