Most people view bilingualism similarly to learning how to write computer code: It’s a skill you acquire in order to accomplish things.
I know of a couple who live in France: the husband is French, and his wife is Australian. The husband once informed me that he knows when an argument with his wife has crossed from a simple disagreement into something he should be worried about when she starts speaking to him in French. English, he explained, has always been ‘their’ language – it’s what they spoke when dating. In public they speak French, but in private, just between themselves, they speak English – it’s the language these two bilinguals have agreed on.
‘When I hear her speak French,’ he said with a sudden expression that can only be described as doom, ‘I start making up the sofa in the living room to sleep on.’
Bilinguals routinely agree on a language they use between themselves. There are many reasons for the choice, ranging from practicality (if one of the bilinguals is much less fluent in one shared language over another) to emotions, such as with my friend and his Australian wife. Deviations from this agreement often get negative reactions – people wonder why you’ve broken the language agreement. Often the first assumption is that you are angry with them.
From the Mouths of Babes
To see how primal language agreement is, we can consider bilingual children, who often react quite violently to a sudden change in language between themselves and a playmate or family member. Bilingual children will easily settle on an agreed language when playing with each other, and if one child suddenly switches to another language they can become very upset, even angry. Certainly no one has instructed these children to adhere to some rules of language agreement – it is instinctual.
I have another friend with a much sadder story than the first: He married a Russian woman and they had a daughter, then went through a rather bitter divorce. During the happy times the Mother spoke English to her husband and daughter. After the divorce, she switched to speaking exclusively Russian, presumably to make a clean break from her past with him.
This was incredibly upsetting to the daughter, who understood Russian but had agreed on English with her Mother. Although the switch had nothing to do with her, she suffered, wondering why her Mother was suddenly ‘cold’ towards her – a perception having to do entirely with the switch to Russian, as my friend admitted the words themselves were quite loving and affectionate.
The rule of thumb is: If you customarily speak one language with a bilingual friend, don’t change it up – unless you’re trying to make a point!