Bhagavad Gita: Chapter 13/Verse 20

कार्यकरणकर्तृत्वे हेतुः प्रकृतिरुच्यते ।


पुरुषः सुखदुःखानां भोक्तृत्वे हेतुरुच्यते ॥१३- २०॥

kāryakaraṇakartṛtve hetuḥ prakṛtirucyate ।
puruṣaḥ sukhaduḥkhānāṃ bhoktṛtve heturucyate ॥13- 20॥

It is said, material nature is the cause in the agency of cause and effect. It is said, spirit is the cause in the experiencing of the pleasures and pains. 


kāryakaraṇakartṛtve (kārya + karaṇa + kartṛtve) (neuter, locative, singular) = in the agency of cause and effect

hetus (masculine, nominative, singular) = cause 

prakṛtis (feminine, nominative, singular) = material nature 

ucyate (present tense, 3rd person, singular) = it is said 


puruṣas (masculine, nominative, singular) = spirit 

sukhaduḥkhānām (sukha + duḥkhānām) (neuter, genitive, pluarl) = of the pleasures and pains  

bhoktṛtve (neuter, locative, singular) = in the experiencing 

hetus (masculine, nominative, singular) = cause 

ucyate (present tense, 3rd person, singular) = it is said