An infinitive is a verb combined with the word to. Most often, an infinitive acts as a noun in the sentence. Less frequently, it acts as an adjective or an adverb.
Generally, it is not common to split to and the verb except for when you want to emphasize the verb.
Q. Fill in the blanks.
(i) I am going ____ (learn) English.
(ii) It is common ____ (make) a grammar mistake.
(iii) Did you come ____ (clean) my house?