"Are Paris and London the same?"
Translation:Zijn Parijs en Londen hetzelfde?
So if both are "de" words, then it would be "dezelfde", and if both are "het", "hetzelfde". But if there is one "de" and one "het", then is it "dezelfde", or is it dependent upon which noun comes last in the comparison (e.g. "Zijn (de) klei en (het) porselein de-/hetzelfde?")?
Actually what you're saying is not correct. This is a different usage of hetzelfde. You probably need somebody that can explain this better than I do, but I'll give it a shot.
If hetzelfde can be replaced by gelijk or eender it always has to be hetzelfde in this kind of sentences (in some cases it can be changed to dezelfde, but then the meaning changes), similar examples:
- De mannen denken hetzelfde (The men think the same thing)
- Deze twee boeken zien er niet hetzelfde uit (These two books don't look equal)
- X en Y zijn niet hetzelfde (X and Y are not the same/X and Y are not equal)
The second type does depend on the article that is replaced by dezelfde/hetzelfde:
- Het is niet hetzelfde gordijn (It is not the same curtain - hetzelfde because gordijn is a het woord)
- Het zijn niet dezelfde gordijnen (It are not the same curtains - dezelfde because gordijnen is plural, so de)
See explanation in Dutch here.
That is correct, it is important to keep the two uses of "hetzelfde" apart. In Susande's second usage, dezelfde/hetzelfde is a demonstrative determinder. It identifies two things as being one and the same.
However, "hetzelfde" can also serve the function of an adverb*. In that case it performs a comparison and concludes that two (or more) things are (or look, smell, feel, appear, etc.) the same. In this case, the word is not connected to any single object and so it does not reflect the gender of any particular noun.
Sometimes there is some overlap between these two uses, and you can use one or the other.
*or a predicative adjective, like in this sentence.
Some 75% of the nouns take de, so when you're not sure, that's your best bet. (And if you use the wrong one…the less common the word, the less people will notice, with very uncommon words native speakers don't even know.)
Regarding new words: if it's any compound word (including stuff you just made up), it gets the same gender of the last part, e.g.:
- het geval = the case
- het slabidabigeval = the slabidabi case (some nonesene I just made up)
- het bord = the plate (existing word)
- het moederbord = the motherboard (het, because of bord)
For other new words it gets the same gender as a common word that either looks the same, has a strong link to it or has the same meaning. With very new words this may be arbitrary. In the mid 90's a new (domed) football stadium was built in Arnhem: Gelredome. Both de Gelredome (because it's called dome and the dome = de koepel) and het Gelredome (because it's a stadium and the stadium = het stadion) are used. Both are fine, people usually have a personal preference for one or the other. In most cases they probably don't know why and they just use either what they feel sounds good (yes you'll get a feeling for it) or what the majority does (yes there is some link between the two).
For other recent loanwords consensus was reached, e.g. de computer, de cd, de (micro)chip. Using the other article in these cases is considered wrong.