At school we learnt that it is correct to say either English or the English language, but it is a mistake to say just 'English language' without the.
Yet I recently happened to read an article in some learning materials about New Zealand and the author many times wrote just Maori language (without the), although a few times he did it with the – the Maori language. How is it possible? Was it a mistake of a native speaker or the rule itself has become shaky?
Here is the context:
Recently, Maori language became a core school subject. Many New Zealanders encourage this development, recognising that Maori language is an integral part of New Zealand’s culture. The Maoris probably originated from around Japan, as the pronunciation of the Maori language is very similar to Japanese, and the Japanese can often say Maori words more convincingly than the average non-Maori New Zealander.