How to Find and Listen to One Actor's Lines
Playphrase.me editorial
Open Search & Learn, choose English, and select Select Actor. Type a name into Search actor..., then choose the person from the list. The route, actor label, search placeholder, and result set all switch to that actor's Search & Learn context.
You can now leave the main phrase field empty and listen to the available lines, or search for an expression such as you know only within those lines.

Check that the actor scope is active
After you choose Brad Pitt, the actor label reads Actor: Brad Pitt and the main field shows Search Brad Pitt's phrases. Together, they confirm that the general search has changed to one actor's collection.

The two search fields have different jobs. Search actor... finds a person to select. Search Brad Pitt's phrases searches for a phrase within the selected actor's lines.
Listen first or search within the collection
Leave the main field empty and start playback to hear what is available. The lines, scenes, and roles will change while the selected actor stays the same.
To narrow the collection, enter you know in Search Brad Pitt's phrases and press Enter. The Actor: Brad Pitt label remains in place, so the results are limited to his lines rather than the general search.
Start with stricter matches
Leave Include possible matches off at first. This keeps the actor collection to the stricter set of matches.
If the collection is too small, reopen the actor picker and turn the setting on. The broader set can include less certain matches, and some may be wrong. Check them by ear and skip doubtful results.
On a phone, actor selection opens in the Actors panel. The same name field and Include possible matches setting appear at the top.

Change the actor or return to general search
Open the current actor selection to choose someone else. To remove the actor scope, clear the selected name. The label returns to Select Actor, and the main field searches the general collection again.
This workflow belongs to Search & Learn. It is separate from the Cast and Actor Voice filters in Clip Search, which do not create the same actor-scoped Search & Learn context.
What actor search may not include
Playphrase.me searches only the material in its corpus, not an actor's complete filmography. If a familiar line is missing, its film or series may not be in the corpus, or that particular line may be absent from the available material.