Expensil? Team ?

We were playing with a subset of his hotwheels collection. The game was about 4 rogue cars hitting the car I was driving, and all of them would end up being upturned. 

Then the firefighters vehicles(fire truck, fire chief car, etc. )  and police guys ( the SWAT van, police cars, etc. ) get there with all their cars/trucks. 

Because it was there and needed to be used, a dump truck also gets involved in burying a car that couldn't be resuscitated. 

 I was being given directions: "Papa, get those two white police cars here together. They're a team" 

"Whats a 'team', Nishu? " 

"A team, is .. like .. a red team, blue team, .. "   (heard it at school, I'm thinking) 

"Nishu, a 'team' means a group of people.. "

(hastily added)"or .. cars, that work together to .. get to a goal they all want to get to" 

Just as I was regretting my choice of words (goal ? - I'm sure he was thinking football) . .. he just nodded.

"Ya ya .. now, these cars.. " 

I interrupt again .. " So, what is a team ? " 

"Team is a group.. of ...people, cars.... "

I tried paraphrasing .. " yea.. a group that wants to do the same thing" 

"Ya ya... now you need to get these cars.. be careful, they're expensil "  

I couldn't help interrupt "...expensive" 

"Yea.. expensive.. " 

I say .. " expensive means costly" 

I get that too-quick nod again. 

"So, what does expensive mean? " 

"Expensive means, costly" 

"So what does costly mean? " 

"Costly means.. expensive" 

Again, I realized the folly of using another word he wasn't exactly clear on. 

"Costly means.. it takes a lot of money to buy. Expensive,  means the same thing  " 

There was a pause.  I think that registered. 

"Ya.. ok. get these police cars through here, and don't damage them.. " 

I nod happily - feel a sense of accomplishment.. of teaching while playing..   until

 

"..they are expensil " 

..Sigh....