"The little boy runs away from the chair, onto which an ugly big hairy spider is climbing up."
Translation:Attól a széktől fut el a kisfiú, amelyikre felmászik egy csúnya nagy szőrös pók.
It's the Hungarian way :)
In English, relative clauses usually come right behind the noun, so their position shows that the noun is being modified.
In Hungarian, they usually use a signal word such as ott "there" or az "that" to show that you are talking about a specific place or thing, and the specifier (the relative clause) later than completes the specification of the place or thing. We usually don't translate those into English.
Just to throw in some confusion... while you are definitely being taught this rather emphasized structure here, this is certainly not the only way. This sentence just strongly emphasizes that one chair. Out of the many chairs, the one that the boy runs away from is this specific one.
But we don't always need to do that, do we? What if there is only one chair in the room? The English sentence still stands. Dare I say, it fits that situation much better. Especially with the comma in there.
But the Hungarian sentence will change. It will more closely resemble the English structure. The noun (szék) will move back to the end of the first clause, and the relative clause will have another, less specific relative pronoun (I think that's what they are called, right?) So, here it is, one chair, one boy, one big hairy spider:
"A kisfiú elfut a széktől, amelyre felmászik [or, to be more progressive: mászik fel] egy csúnya nagy szőrös pók."
There you have it.
I will try to find the discussion about "amely" vs "amelyik", it may come in handy here...
Here it is:
Does hungarian have a strict order for adjectives to go in like english, and if so, what is it? In english, for example, it sounds MUCH bettee to say "the big ugly hairy spider," as opposed to "the ugly big hairy spider." Its one of those weird rules you just naturally learn though, not one taught in schools usually.
https://www.google.com/amp/s/dictionary.cambridge.org/us/amp/british-grammar/adjectives-order <-- this link has an example of the english adjective order.
There is a natural order but, like English, it is not taught in school, more like learnt instinctively. (And probably no one could tell you what it is, only if some order sounded weird or not.) I have recently seen an essay, maybe a thesis, analyzing this very thing. It was more like describing the existing phenomenon, not establishing a rule.