Question

which sentence does not contain an infinitive? i need to study tonight. he enjoys reading books. she hopes to succeed. we plan to visit soon.

Explanation:

An infinitive is the base form of a verb usually preceded by "to".

1. "I need to study tonight." has the infinitive "to study".
2. "He enjoys reading books." uses the gerund form "reading" (not an infinitive; there is no "to + base verb" here).
3. "She hopes to succeed." has the infinitive "to succeed".
4. "We plan to visit soon." has the infinitive "to visit".

Answer:

He enjoys reading books.