Forgetting French

Some months ago I met a Japanese woman who, I had heard, spoke French. Being then a total beginner to Japanese, after a few sentences in Japanese I asked if we could speak in French. Her answer? 'Le francais, j'ai oublié.' It turned out that she had forgotten. The whole of French.

Three months later - this Christmas - I went to Switzerland and found myself trying to speak French.

Ordering drinks I struggled to remember basic words, even 'please' and 'excuse me', as the Japanese popped into my head more quickly. People asked me questions and I replied, unhesitatingly, with a stream of 'はい, はい, はい'. The word はい (yes) sounds the same as the English 'hi', so my stream of Japanese
perhaps made me seem like some crazy Brit with an extreme need for acknowledgement, something like
this:

French waitor: Bonjour
Me: Bonjour
FW: Would you like something to drink?
Me: はい. Coke, please.
FW: Yes, hi... Something to eat?
Me: はい, s'il vous plait.
FW: ... Is that all?
Me: はい.
FW: ...

Sentences like 'un coca, おねがいします' sometimes fell, panicked, out of my mouth. 

I wasn't really speaking French or Japanese, but some conflation of what I was most used to saying in 
both; basically 'Foreignese'.

It seems that there's only enough room for one studied language in my brain, and Japanese is steadily pushing 
out French as sole occupant. Most likely Harry Hill has crept into my head somehow, inviting French in one
corner and Japanese in the other to: 'FIGHT!'

I don't mind. In fact I'm pretty happy at this development. In September, starting out in Japanese, to say anything
at all was a struggle. I wished I had the seven years' learning behind me that I already had in French. I've learned
two things: 

(1) Immersion works. From day one, my language school spoke to me solely in Japanese. In three months
I have learned not quite, but close, to the amount I learned in seven years of French lessons.

(2) Escaping immersion pays, too. It was impossible to see that I'd progressed from within Japan, because
I was constantly using Japanese, and being made aware of how much I *didn't* know. Being in Switzerland and realising
that most of the things I could say in French I could say in Japanese, and more naturally at that, made me proud 
of my Japanese.

To desu or not to desu

My mind has recently been blown (see Fig.1) by the information that です (desu), as used in sentences like:

わたし は Charlotte です

(Watashi wa Charlotte desu)

I am Charlotte 

Or 

そら は あおい です

(Sora wa aoi desu)

The sky is blue

Is not an equivalent of the English verb 'is', and is not actually a verb at all. 

Fig.1

The 'desu' in a Japanese sentence is not a verb but, rather, just a politeness marker. In case the sentence 'the sky is blue' sounded a little rude the first time. In the sentence sora wa aoi desu (the sky is blue) the desu isn't actually needed, unless you're trying to be polite: remarking to your boss that the sky is blue, for instance (and probably receiving a withering look for wasting time..) 

The は (wa) is not a verb, either. It is a particle, marking out the sentence's topic: the sky. 

So the sentence translates literally as: 'as for the sky, blue'. No verb.

This leads me to my second recent realisation about the Japanese language... 

Often in Japanese, words that in English we would call adjectives behave like verbs. Yes, あおい (blue) despite being called an adjective, actually acts like a verb. The result? Here in Japan, the sky blues. My bag reds. Mountains big and a mouse smalls. 

This has had little impact on my actual learning of the language so far, except perhaps a slight suspicion when my teachers insist that desu must be used in every 'otherwise' verb-less sentence. I and hundreds of others are being trained to speak such polite Japanese that, apparently, we are actually identifiable on opening our mouths, by some members of the public:

 'How polite, you  don't happen to go to 東京日本語学校...?'