Miss Henderson: It was a cruel, dirty trick you played, Monsieur Poirot.
Poirot: I do not approve of murder. Mademoiselle.
The Adventure of Johnnie Waverly - S1-E3
Miss Lemon: [proudly showing her filing system] Type of case: Abduction. Addiction. Adultery - see also under marriage. Bigamy - see also under marriage. Bombs...
Hercule Poirot: See also under marriage? (00:04:00)
Hastings: Where's Mrs. Japp tonight, then?
Inspector Japp: She can't abide fireworks.
Poirot: Ahhh, the noise disturbs the delicate sensibilities of many ladies...
Inspector Japp: Maybe, maybe. I think it's more that she doesn't like to see people enjoying themselves. (00:02:00)
The Adventure of the Clapham Cook - S1-E1
Hastings: It's a wonderful day. Just fill your lungs with that air!
Poirot: No, my poor friend, this sort of air is intended for birds and little furry things. The lungs of Hercule Poirot demand something more substantial: the good air of the town! (00:26:00)
Answer: He definitely says "Belgian", but the subtitles get it wrong and show him saying "American."
Wblank71