These are reflexes of Proto-Germanic *"ganganą", from Proto-Indo-European *"" 'to step', which also gave Lithuanian "žeñgti" 'to stride', Greek "kochōnē" 'perineum', Avestan "zanga" 'ankle', and Sanskrit "jáṁhas" 'step', "jaṅghā" 'shank'. Therefore, the case of English "go" is not unique among the Germanic languages, and it would appear that most have in a like manner reproduced equivalent suppletive conjugations for their words for 'to go', suggesting a cyclical change patterned after the state of affairs in Proto-Germanic. The verb may be combined with various prepositions to form phrasal verbs such as "go around" and "go off". The verb "go" is used to form the "going to" future, in sentences like "I'm going to finish my work today." In perfect forms of the verb ("have gone", "had gone", etc.) the past participle "gone" is often replaced by that of "be", namely been. For example:  For details of this usage, see "have been".