"Am I the one that you want?"
Translation:Ben ik degene die je wilt?
diegene is mogelijk i.p.v. degene (https://onzetaal.nl/taaladvies/advies/degene-diegene) - wil kan i.p.v. wilt (https://onzetaal.nl/taaladvies/advies/je-wil-je-wilt) - Ja, "degene" en "wilt" zijn beter, maar "diegene" en "wil" zijn niet fout.
Dutch has 3 genders: male, female and neutral. We use "de" for male or female, and "het" for neutral. We say "de man" (= the man, so male), "de vrouw" (= the woman, so female) and "het huis" (= the house, which is neutral). Diminutives get "het" ("het bootje"= the little boat), plurals always go with "de" ("de huizen"=the houses), and plural diminutives have "de" too("de bootjes"= the little boats)
"De" goes with "degene" and "die" or "deze" "Het" goes with "hetgene" and "dat" or "deze"
In this sentence, we are talking about a person, and the language assumes that is either a male or a female, so we use "degene" (rather than "hetgene"), and also "die" (rather than "dat")
I hope I was able to help you, and if you have any questions, feel free to ask me!
I split this explanation in three parts, long story short: could be grammatically correct with a small modification (1), but would be very weird (2), and is not a possible translation for this sentence (3).
1) The thing is, grammatically, that wouldn't be incorrect (if you say 'wil' rather than 'wilt'; long story short, the verb 'willen' is irregular and even the dutch have their struggles with it sometimes: full conjugation here https://nl.wiktionary.org/wiki/willen/vervoeging ).
So "Ben ik degene die jou wil?" is a grammatically correct sentence
2) However, that'd make for a weird sentece, as 'jou' is only used as an object, so the sentence would make little sense. Think along the lines of "Am I the one that wants you(/him/her/etc.)?" You wouldn't ask yourself if you are the one that wants someone else.
3) The example there leads us to why it isn't even the translation. In "Am I the one that you want", 'you' can be either the object or subject of the clause, but as 'want' can only belong to 'you' here, it has to be the subject of the clause. That's why only "je" or "jij" would be correct here.
If anything is still unclear, please message me again!
I suppose you meant "Am I the one who wants you?" there, but that'd be "Ben ik degene die je/jou wil(t)" (for the "willen" conjugation and explanation see my other reactions to this sentence) but to prevent ambiguity I'd recommed using 'jou'.
In "Is ze diegene die je belt", it's a bit different indeed, 'bellen' is regular, so 'belt' can either belong to 'ze' or 'je'. And because 'je' can be either subject or object, this sentence is ambiguous.
So if the meaning is: "Is she the one who(m) you call?" (you call her)
it could be this: "Is ze/zij degene die je/jij belt?"
and if the meaning is: "Is she the one who calls you? (she calls you)
it could be like this "Is ze/zij degene die je/jou belt?
notes: "ze" and "zij" can both be used for both sentences, there's no difference in grammatical structure here ('zij' is stressed more than 'ze', but that's it). Also notice how 'je' is used in both sentences, so while correct, it's ambiguous to use (see above).
I hope that answers your question, if it doesn't, feel free to message again!