# What is the name of the NLP technique that determines "who did what to whom" given a sentence?

Within a piece of text, I'm trying to detect who did what to whom.

For instance, in the following sentences:

CV hit IV. CV was hit by IV.

I'd like to know who hit whom.

I can't remember what this technique is called.

In your example CV was hit by IV, the task is to identify the verb "hit" carried out by the actor "CV" affected "IV" the recipient.