Speaking from personal use rather than actually knowing any rules, I'd say:
"x ser ut som z" is used for appearance only (x looks like z). You can specify other type of likness with e.g "x låter som y" (x sounds like y) etc.
"x är som z" is used more for z as a "concept" than one specific thing, e.g "mitt rum är som en bastu" (my room is like a sauna).
"x är lik z" is usually about appearance, but can be for other likeness too. To avoid misunderstanding, one should usually specify that it is not appearance that is meant, unless it is obvious (so "Du är lik Mr Bean" (~you are like Mr.Bean) would typically be understood to mean they look alike, if you want it to mean in how they behave, one preferably should say e.g "Du liknar Mr Bean till sättet". Though if you say "Den här låten liknar nationalsången" (This tune resembles the national anthem) it can't really be about looks, so no specification is needed.)
"x liknar z" is almost always interchangeable with "x är lik z", except for a few set phrases.
"x är likadan som z" indicate higher level of likeness, and can often be translated to "same" rather than "similar". Sometime one will her one Swede say e.g "Jag har samma bil som du", and the other might teasingly point out "Nej, men du har en likadan bil som jag", since the first one kind of mean that there is just one car and we both have it, while the second means the two cars are of the same make and model. (I have the same car as you)
Generally, continuous forms of verbs that have a static meaning should be avoided in English. Sometimes they get another meaning, like is seeing which means date instead of see.
Other examples of stative verbs are “like”, “have”, and “taste”. The progresssive form cannot be used for talking about habits or routines.
And other users, please don't downvote questions like this, at least not when they're already at the bottom of the page. It's quite legitimate to ask questions about English too, and the answers to questions like this one can be very useful.
so as a native speaker, do you think infinitive "to sail" or does it seem like a different meaning? I ask, since you translated it like a gerund.
Also, do you think in English, or any other language? Not to be personal, but since you have/or are studying so many languages, it seems unimaginable that you could know so many languages and think in several. I lived in Germany for a year(many years ago), but there are some German words or idioms that say the meaning so much better than in English, that they still come to my mind more than the English words. Some languages capture the meaning of the words so much better, they should be taken into English. Thanks.
For some reason I thought that was the common way of saying it in English. I tried googling it now but I get somewhat confusing results: Wikipedia gives it with 'to sail', but I get more hits on Google for 'sailing is necessary' than for 'to sail is necessary'. Anyway it doesn't really matter in itself, the Swedish infinitive corresponds to both in English in cases like this. It's more a matter of which one fits best in which context in English.
I wanted to come back here because I thought of something yesterday that I wanted to add: while we don't have a gerund and the active participle (in this case seglande) rarely works as a subject, we have a lot of abstract nouns, in many cases created from verbs. In this case, that form is segling, which is not a verb at all, but it's a so-called verbal noun. It can fill any function other nouns can. So you could say either att segla är kul which would be 'sailing is fun' or 'to sail is fun', but also segling är kul which means 'sailing [the activity] is fun'.
As for what language I think in, it varies. I'm not always aware of it, but I've noticed I usually think in English when I'm on here. I can think for a while in one language, even one I don't know that well, and then switch to another one… it varies a lot.
Yeah, it's probably not correct in this example I'd say, but there ARE possibilities out there for using the continuous 'you are looking like' in a colloquial manner.
Say your little brother is growing up and wearing nicer clothes and your mom says to him, "Hey, you're looking like your brother these days!"
Because you would not use the continuous form of to look here. I'm afraid I can't tell you why because I only speak my language, not study it haha. Perhaps someone with a better linguistics background can help. The best I can do is link this article which seems to explain some rules to follow when deciding whether to use the continuous tense or not.