If you cannot speak and write English well, not only will you find it extremely difficult to find a job, but you probably won’t qualify for any sort of work visa in the first place. You will, however, be relieved to hear that you won’t be required to speak Maori (which was made an official language in 1974) as well!
Although New Zealand is officially bilingual and there have even been proposals to replace some English place names with Maori names (hopefully shorter than Taumatawhatatangihangakoauauotamateapokaiwhenuakitanatahu – the place where Tamatea, the man with big knees who slid, climbed and swallowed mountains, known as ‘ landeater’, played his flute to his loved one), English is still the major language of business and spoken by all.
New Zealanders aren’t generally adept at speaking foreign languages; when your nearest neighbours are hundreds of miles away and even they speak English (of a sort), there’s little opportunity to practise French, German or Spanish. Some shrewd New Zealanders with an eye to the future have made great strides in Japanese and other Asian languages, but don’t bank on it. If you don’t speak English well in New Zealand, you will be sunk!
Don’t be fooled into thinking that New Zealand English is more or less the same as Australian English; it isn't. As any New Zealander will tell you, New Zildish is the proper Antipodean version of English and it’s the Australians who have corrupted it. You will find that Australian words and phrases aren’t used in New Zealand (the same applies to American, Canadian and other versions of English). The use of ‘proper’ English often comes across as rather snobbish or superior in New Zealand, where people at all levels of society use New Zealand’s own dialect, even at work.
The main distinguishing characteristic of the New Zealand dialect is to shorten words so that they end in ‘o’, ‘y’ or ‘ie’. For example, ‘ arvo’ for ‘afternoon’ or ‘ kindy’ for kindergarten. Like accents in any country, a New Zealand accent can vary from slightly difficult to understand to completely unintelligible. Nevertheless, whatever variety of English you speak, if you speak it well, you will be easily understood.
The early years of the 21st century have seen New Zealanders of all backgrounds increasingly peppering their speech with Maori words, perhaps a sign that the country is beginning to distance itself from its British heritage and forge its own identity. Until recently, the only Maori words known to most white New Zealanders were place names and terms like haka (the war dance perfomed by the All Blacks rugby team before matches) and kiwi (the small, hairy fruit). But words like kiora (hello), mahi (work) and whanau (family) are being used with increasing frequency, and some popular English expressions have been given a Maori flavour with the inclusion of Maori words, for example, ‘he’s a couple of kumera (sweet potato) short of a hangi (earth oven)’.