Infinitives

Infinitives are the "to" form of the verb. The infinitive form of "learn" is "to learn." You can also use an infinitive as the subject, the complement, or the object of a sentence.

Infinitives as the subject of the sentence.
Example

• To learn is important.

Infinitives after verbs.

Infinitives after verbs appear in one of three patterns:

• Verbs + Infinitive.

      agree - decide - learn - plan - refuse - wait.

• Verbs + Object + Infinitive.

     advise - force - invite - get - remind - urge.

• Verb + (object) + infinitive.

      These verbs can be followed by the infinitive with or without an object.

       ask - expert - need - promise - wish - would like.

Find a list of verbs followed by infinitives here: http://www.englishpage.com/gerunds/infinitive_list.htm

Practice

http://www.englishpage.com/gerunds/gerunds_infinitives_2.htm

http://www.perfect-english-grammar.com/gerunds-and-infinitives-exercise-1.html

http://www.perfect-english-grammar.com/gerunds-and-infinitives-exercise-2.html

http://www.englisch-hilfen.de/en/exercises/structures/gerund_infinitive.htm