his, her, your, or their research
Él está absorto en su investigación.
He is engrossed in his research.
Su investigación se retrasó y va a tener que quedarse en Quebec.
His investigation was delayed and he will have to stay in Quebec.
— Roma (2018)
Él ha descuidado su investigación últimamente.
He has neglected his research lately.
De seguro su investigación dará frutos.
I'm sure your research will bear fruit.
Su investigación no tiene la capacidad para cambiar el destino.
Their research has no power to change fate.
— Legado en los huesos (2019)