which efforts were made to revive it?
Businesses adopt the trend as it became apparent that using "te reo" made customers think of a company as "committed to New Zealand" and it became increasingly heard in the media and in politics.
Māori language
Beginning in about 2015, the Māori language underwent a revival as it became increasingly popular, as a common national heritage, even among New Zealanders without Māori roots. Surveys from 2018 indicated that "the Māori language currently enjoys a high status in Māori society and also positive acceptance by the majority of non-Māori New Zealanders".

As the status and prestige of the language rose, so did the demand for language classes. Businesses were quick to adopt the trend as it became apparent that using "te reo" made customers think of a company as "committed to New Zealand". The language became increasingly heard in the media and in politics. 
who said english is our major window on the modern world UNANSWERABLE how is this language classified? It is an Indo-European language and belongs to the West Germanic group of the Germanic languages. which are some of the dialects? British English (BrE) and North American English (NAE) and Australian and New Zealand English what are the notable features of the first dialect? It revolve around the pronunciation of the letter R, as well as the dental plosive T and some diphthongs specific to this dialect. does the last dialect has any non english influence? Yes, influence of Māori in what way is this influence seen? It is mostly lexical; many local everyday words have been borrowed from it where did this language which influenced english originate? Current anthropological thinking places their origin in eastern Polynesia, mostly likely from the Southern Cook region does it have any status officially? Yes, by the passing of the Māori Language Act 1987
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Māori language [SEP] Revival since 2015
Beginning in about 2015, the Māori language underwent a revival as it became increasingly popular, as a common national heritage, even among New Zealanders without Māori roots. Surveys from 2018 indicated that "the Māori language currently enjoys a high status in Māori society and also positive acceptance by the majority of non-Māori New Zealanders". As the status and prestige of the language rose, so did the demand for language classes. Businesses were quick to adopt the trend as it became apparent that using "te reo" made customers think of a company as "committed to New Zealand". The language became increasingly heard in the media and in politics.