I can understand that the Swedish team wants to teach the "correct word" for baby. However, "spädbarn" sounds rather formal and "bebis" is more common, at least in spoken language. For example, I have never heard anybody say "Åh, vilket gulligt spädbarn!".
But "bebis" is an odd word, just like "kex" and "keps":
en bebis (from plural babies)
ett kex (from plural cakes)
en keps (from plural caps)
I know many people who use that word. I thought it was a Stockholm thing, but then I heard it from someone from Skåne. – Btw one problem with bebis is that nobody can agree on how to spell it. DN writes this about why they prefer bebis over bäbis, but actually they're not quite right: SAOL claims baby is the best word.
They even recommend to use bebisar for plural. Oh and they give an alternative spelling too: bebi, which means there are 4 spellings of this word in SAOB.
I agree with you, baby is a hopeless word in Swedish, hard to decline and makes you wonder how it should be pronounced.
kex is a loan word from English cakes, but they didn't realize they used a plural form. The same happened with keps which is borrowed from English caps – en keps is a cap as in a baseball cap. So this has happened at least twice.
There's a big controversy about how to say kex in Swedish, in Stockholm it's said with a hard k sound (which follows the original pronunciation) and in Gothenburg it's said with the soft ɕ sound (this follows the rule for how k is pronounced before vowels). Immature people from both places regularly have big fights over this but both are really absolutely fine.
The pronunciation of "kex" and "Keks" isn't really the same. I'm not good at describing something like that, but "kex" has a softer "ending sound" and depending on were you live the beginning is more like a "sh" sound than a k, whereas "Keks" always starts with a hard k. Compare it on Forvo to hear the difference: http://de.forvo.com/word/kex/#sv and http://forvo.com/word/keks/#de (I can only recommend the first one, the second one is quite strange - I'm a German native).
But you're right with the meaning - what we Germans call "Keks" is usually called "kex" in Swedish by Swedes, in my experience. I personaly would translate "kex" as "cookie" because of that, but somehow this doesn't seem to be the right word. I have heard some Swedes call cookies "cakes" when they speak English (without noticing their mistake), but I don't know why that happens.
First of all, I'm a native German too :) I see what you mean when you're talking about the "sh" sound in "kex" or the different ending, thank you! I will change my comment to "similar" then, instead of "the same".
Also it's good to know that I was at least right with the meaning (which was actually the main point of my question).
The only difference is the origin of the word. Bebis originates from the English plural form babies, but is singular in Swedish (plural is bebisar) and was introduced in Swedish in the early 20th century. Spädbarn is much older and constructed from the words späd (early in development (or frail)) and barn (child).
There are actually only two words in Swedish, since Swedish definites are suffixes. It's because these are two different languages, and you can't EVER, with any two language pairs, count on always translating word for word. Even between languages as close as Portuguese and Spanish, and sometimes between dialects in the same language.
I say "scone" to rhyme with "gone", but it's a regional thing. My grandparents were all Australian but one was born in Plymouth, England, to a father born in Oxford. https://www.theguardian.com/science/2017/apr/23/how-do-you-pronounce-scone-answer-says-a-lot-english-language-day-shakespeare-birthday