What happened today? Asked the magician

Yesterday I went to a magic show and I was part of a clever trick. First of all, the magician arranged 36 cards in a 4 x 9 grid as follows:

Then they called me on the stage. I felt a little bit uncomfortable, after all I didn’t want to be sawn into two pieces! As the magician explained what I had to relaxed: I just had to point a card of my choice while they were turned around. Then they would guess which card I pointed by asking a single question to the assistant. "Wait a minute" I objected: "This should be simple, you could just ask your assistant which card I pointed!". "It’s not that simple" they replied: "I will only ask my assistant what happened today".

At this point I was curious. They turned around and I pointed at the first card. Then they turned back to us and the following conversation took place (M is the magician, A is the assistant, who saw which card I pointed):

(1) M: what happened today?

A: An apple fell inside a bucket.

M: That’s the seven of hearts!

I was intrigued, the magician got it right! They asked me if I wanted to retry and I accepted: they turned around again and I pointed another card. Then they turned back to us:

(2) M: what happened today?

A: A cow mooed to my cat.

M: That’s the five of hearts!

Amazing, it was right again. Clearly the magician and the assistant had an agreement on a sort of code. I wanted to figure out the code, so we repeated the game a lot of times:

(3) M: what happened today?

A: A bomb killed Jane.

M: That’s the seven of diamonds!

(4) M: what happened today?

A: A dog hit a bus.

M: That’s the ten of spades!

(5) M: what happened today?

A: Joe ate an apple.

M: That’s the ace of diamonds!

(6) M: what happened today?

A: A ram attacked Mike.

M: That’s the jack of hearts! Poor Mike by the way…

(7) M: what happened today?

A: A chestnut tree blocked Peter.

M: That’s the six of diamonds!

(8) M: what happened today?

A: Janet kissed Alice.

M: That’s the king of diamonds!

(9) M: what happened today?

A: Bob met Diane.

M: That’s the three of clubs!

At this point I was truly impressed: they got it right every single time! I was sure that no information was given by the assistant other than the answer to the silly question. The magician asked "do you want to try one last time?". "Sure!" I replied.

(10) M: what happened today?

A: A meteor destroyed a cyclamen.

M: That’s the ace of spades!

Sure enough it was right. At this point something came to my mind: I thought a little bit and… I guessed the "code" used by the magician and their assistant! So I pointed a card and I told the magician:

(11 – QUESTION) Today a dog climbed a chestnut tree.

"Well done", he replied: "you cracked our code".

How could the assistant communicated my cards using just their answers?

What is the last card I pointed?

I EDITED this post on 2020-10-20 to clarify that the whole trick is not just about pre-memorizing 36 phrases or something like that.

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Additional cards pack 1 (2020-11-02)

Yesterday I come back to the magician’s place, they immediately recognized me and said: "I saw that you posted my trick on PSE!". "I didn’t lose time! But my friends there need a little help to figure out your code". "I see… someone replied but no answer is correct. Look at this for example":

(12) M: what happened today?

A: John cut an apple tree.

M: That’s the eight of spades!

"I know what’s going on here" I said, "you chose this particular card just to prove that both @Johnathan Ashley and @Joe Ferndz are wrong". "Sure", they replied, "look at these too":

(13) M: what happened today?

A: A walnut fell on Alice.

M: That’s the seven of clubs!

(14) M: what happened today?

A: A cat scratched Philip.

M: That’s the Jack of hearts!

(15) M: what happened today?

A: The eraser rubbed out a rose.

M: That’s the ace of spades!

(16) M: what happened today?

A: A locomotive ran over Angelina.

M: That’s the seven of diamonds!

"That’s it" said the magician "I hope that your friends will be able to guess our code by looking at this additional pack of cards". "So do I, see you soon." I replied, and left.

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Additional cards pack 2 (2020-11-10)

Yesterday I come back to the magician’s place again seeking for a little bit more help for you, my friends!

(17) M: what happened today?

A: Leyla planted an orchid.

M: That’s the ten of diamonds!

(18) M: what happened today?

A: a mushroom grew over an oak.

M: That’s the nine of clubs!

(19) M: what happened today?

A: a grape fell on Donald.

M: That’s the four of clubs!

(20) M: what happened today?

A: Daniel punched Jonas.

M: That’s the two of diamonds!

(21) M: what happened today?

A: a watermelon rolled on a spider.

M: That’s the three of spades!

(22) M: what happened today?

A: a taxi hit a cow.

M: That’s the five of clubs!

(23) M: what happened today?

A: Paula fed a crocodile.

M: That’s the ten of clubs!

(24) M: what happened today?

A: a cherry fell from the cherry tree.

M: That’s the nine of hearts!

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Additional cards pack 3 (2020-12-01)

(25) M: what happened today?

A: An apple rolled over a pear.

M: That’s the four of spades!

(26) M: what happened today?

A: a lion scared Carola.

M: That’s the seven of spades!

(27) M: what happened today?

A: Emma talked to William.

M: That’s the eight of diamonds!

(28) M: what happened today?

A: A hammer destroyed a train.

M: That’s the six of spades!

(29) M: what happened today?

A: Sophia built a tower.

M: That’s the nine of spades!

(30) M: what happened today?

A: David milked a cow.

M: That’s the queen of hearts!

(31) M: what happened today?

A: Isaac bought a piano.

M: That’s six of clubs!

(32) M: what happened today?

A: An elephant ate an pinapple.

M: That’s the jack of spades!

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Additional cards pack 4 (2020-12-14)

(33) M: what happened today?

A: A drum deafened Christian.

M: That’s the eight of hearts!

(34) M: what happened today?

A: a monkey hid over a lime tree.

M: That’s the three of diamonds!

(35) M: what happened today?

A: Selena bought a tangerine.

M: That’s the ace of clubs!

(36) M: what happened today?

A: a nutcracker smashed a cherry.

M: That’s the two of hearts!

(37) M: what happened today?

A: a rose stang Erika.

M: That’s the jack of clubs!

(38) M: what happened today?

A: a palm broke a truck.

M: That’s the five of diamonds!

(39) M: what happened today?

A: a sprout poisoned a cat.

M: That’s the king of hearts!

(40) M: what happened today?

A: a chestnut tree grew a chestnut.

M: That’s the four of hearts!

Now that you have the "code" for all the cards it shouldn’t be difficult!

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Hint 1 (2020-12-28)

Yesterday I came back to the magician’s place again. "I saw that no one got my code yet, and I’m very sorry about it" they said. "What should we do now? Could you give us an hint?" I replied. "It’s not time for a hint but…

"What do you mean? What should they look for in particular?"

"Oh, I see it now. Thank you". Can you guess the code now?

_{Credits: I drew the cards grid using the "playing cards" section of the random.org website.}