Maraming mag-aaral ang pumapasok nang maaga para hindi mahuli.

Maraming means “many” or “a lot of.” It’s formed by adding the linker -ng to the adjective marami when it directly modifies a noun.
Example: marami + -ng → maraming mag-aaral (“many students”)

• Maraming already carries the sense of plurality (“many”), so you don’t need the plural marker mga.
• You can’t say marami mag-aaral because marami must take the linker -ng before a following noun.
  Thus, maraming mag-aaral is the correct “many students.”

The root is pasok (“enter/attend”). The infix -um- creates the actor-focus verbal form. In the present/habitual aspect you get pumapasok, meaning “(they) come in” or “(they) are attending.”
• Past tense (completed): pumasok
• Present/future (ongoing): pumapasok

• Nang (with a single vowel) links verbs to adverbs of manner or time: nang maaga = “early.”
• Ng marks genitives or objects. It cannot introduce adverbs.
  So for “enter early,” you must say pumapasok nang maaga, not pumapasok ng maaga.

Para introduces a purpose clause meaning “so that” or “in order to.”
Para hindi mahuli literally means “so that (they) won’t be late.” It tells us the reason or goal for coming in early.

• Upang is a more formal synonym for “so that,” so you could say …pumapasok nang maaga upang hindi mahuli.
• Para sa usually precedes a noun (para sa iyo = “for you”), so para sa hindi mahuli would be ungrammatical. Use para (without sa) before a verb phrase.