If + subjectThe person or thing that performs the action of a verb or that is described by a verb. E.g.: Andy has never been to Brunei. ("Andy") + auxiliaryA helping verb used with main verbs to express mood, voice and tense. E.g.: I can't stand when I am disturbed. ("can", "am") can be replaced in formalNot belonging to colloquial or everyday speech; official. E.g.: I demand that Mr Smith call the person on whom the committee has decided. English, or for dramatic effect, by the inversionA structure in which a verb or an auxiliary precedes the subject. E.g.: "Here comes the sun." of the auxiliary and the subject, with the if omitted.