関係代名詞のthatは、主格、目的格の2つであり、所有格はありません。

tbd

The relative pronoun 'that' has two states, a nominative case and objective case, but there is no possessive case.

thatには、主格、目的格の２つしかなく、格による形の変化はない。

tbd

'That' has only the two cases, nominative and objective, and it does not inflect depending on the case.