Swedish is, on the whole, pretty easy for English speakers. It's closely related and the grammar is the same basic shape, except simpler.
But there are a few things that are ~pure vibes~ and instinctual knowledge that will be pretty tough for me to get, as a non-native! They're also really interesting to me, as a language nerd.
Swedish has multiple ways to say 'yes'. So far so good, so does English and probably every language. But they have a yes that you deploy only when you're contradicting someone - so like, "Is his hair red?" "Yes" is the normal kind, but "His hair isn't red", "Yes it is" is a different yes.
Things don't just exist, in Swedish. Or, sometimes they do, but if they're a physical object existing in proximity to other objects, they don't. They stand or lie! You have to know whether the thing you're talking about is oriented vertically or horizontally! You can do this in English, of course, but it's not compulsory. Sometimes it's easy - a mug probably stands on the table, a rug probably lies on the floor - but sometimes it's weird. Saucepans stand on the table, for instance. Sometimes people argue about it - should you say that flowers stand or lie on a grave? It depends whether they're in a vase holder or just put on the ground. You can see how this one has poetic and metaphorical potential but it's hard to conjure as a learner.
There are three ways of thinking! Pure thought, having an opinion (random), and having an opinion informed by facts. So you have to speak differently, for instance, if you think a movie is good but haven't seen it vs if you have seen it. Interestingly, having an opinion without facts is the same way you express belief in God or gnomes or ghosts. Probably Swedes feel this in their bones but I have to think about how I'm thinking about it.
There's two ways to express what will happen in the future. Something where it's under our control vs something that's not. "I will go to Berlin" is expressed differently if you're going there on vacation vs being sent by work! Another one with strong poetic potential.
Continuous action is expressed by talking again about sitting and lying or another continuous verb, plus the actual verb. So to express "the children were playing (ongoing)" you would say "the children were sitting and playing". Unless they were standing, or lying down. Or if you don't know/it doesn't fit you use the verb "holding" which I think is cute, it's like being in a holding pattern.
Obviously I'm not good at Swedish so I probably got some of this wrong, but I think it's cool to find these little corners of language where you see a different way of thinking about the world peeking through - not as extreme as some of the languages where you have to express things in terms of cardinal directions or whatever, but interesting anyway!
