A tad is perhaps slightly smaller than a bit. Though of course these are both wonderfully imprecise terms.
I think accepted transliterations are automatically generated. You can report it, I guess, but I would very strongly recommend learning and using Cyrillic.
Sorry, I realise I was unclear - I meant when given the Russian Сергей/Сергея, why doesn't it accept 'Sergei' as the English equivalent (when asking for the English) From your answer though, I now realise that it probably sticks completely to one standard transliteration system, even for names (but I automatically wrote 'Sergei' not 'Sergey', as I have two friends who write 'Sergei' when writing in English).
Oh, good grief. I shouldn't try to multitask. It's my brain that's unclear - obviously you're translating to English here. Yeah, "Sergei" is a common enough transliteration, it ought to be accepted.
If you say "чем" then you need to use nominative case - "больше Сергея" or "больше чем Сергей".
in spite of my having informed DUO twice about the problem of chut-chut, they still haven't made the necessary correction ! I cannot proceed and finish the tree because if I write chut'-chut' with an apostrophe like DUO does, they say it is wrong ! and if I write it without the apostrophe they say it is also wrong !! I am stuck here !
The problem with colloquialisms is that there's loads of them and you have no idea which ones will be accepted. In this case, I wrote "teeny bit", which wasn't accepted.
What does "a tad more"mean? Isn't "a bit more" correct too? I know "tad"only in "tadpole"...
The Russian чуть-чуть is quite close to the Japanese word ちょっと (pronounced chotto) with a similar meaning: slightly, a little, a bit, somewhat.