Learning to pronounce the sounds of a foreign language is very hard. Even learners with an advanced command of grammar and vocabulary can be easily spotted as having a certain mother tongue when they speak their target language. So why is it so hard to master pronunciation?
While we cannot say for sure, some explanations are offered by first-language acquisition research which asserts that the phonology of a language, i.e. a language’s distinctive inventory of speech sounds, plays a unique role in the development of the first language for two main reasons. Firstly, intonation and rhythm are the first speech elements we encounter, even before birth. Phonological units – or phonemes – are those speech sounds that differentiate meanings of words. They are learned very early in life, becoming anchored in our minds. Secondly, after about 12 months, we are so attuned to the speech sounds of our first language that we tend to misinterpret foreign speech sounds and find it hard to articulate them properly. This attunement has been proven in studies with infants and newborns who, when compared with adults, are able to promptly discern every speech sound to which they have been exposed, even where those sounds are not part of the native phoneme inventory. This ability decreases around the first birthday when children recognise those phonemes that are important for their native language.
To take an example: native English-speakers distinguish between /t/ and /th/ sounds through words such as ‘tank’ and ‘thank’, which have clearly different meanings. However, those who have acquired German from birth automatically ignore the difference between /th/ and /t/ because there is no German word where /th/ creates a shift in meaning. The processing of spoken language thereby becomes much faster as small changes in the production of speech sounds are ignored when they don’t matter to meaning. (After all, there is only a small difference between /th/ and /t/ and, while it may sound odd to say <Tisch> with /th/ at the beginning, it doesn’t give us a new word). However, this development also complicates the learning of foreign sounds as it may be precisely these small changes that are important for foreign speech production later on. For Germans, learning English pronunciation therefore means having to reset deeply rooted behaviour to become aware of phonological differences between /th/ and /t/, for example.
Accordingly, early bilinguals will have greater phonological knowledge by being exposed to a greater volume and variety of speech sounds. However, it is not yet clear whether they are more flexible in consciously detecting ‘foreignness’ which could be advantageous in learning pronunciation in an additional language. Research in phonological acquisition in multilingual minds is not as well developed as knowledge concerning grammar or vocabulary. We need further and more detailed studies on difficulties in foreign-language pronunciation and whether this undertaking may become easier the more languages we speak.