We just learned in Greek:
this chair is small is Η καρέκλα είναι μικρή (I karékla eínai mikrí),
my drink is cold is Το ποτό μου είναι κρύο (To potó mou eínai krýo), and your food is hot is Το φαγητό είναι ζεστό (To fagitó eínai zestó).
To say their car is tall you would say Το αυτοκίνητό τους είναι ψηλό (To aftokínitó tous eínai psiló).
You're really saying "the car their is tall" because Greek works a little differently than English.
We can break it up like this:
The - Το (To) - sounds like toh
car - αυτοκίνητό (aftokínitó) - sounds like ah-f-toh-KEE-nee-TOH
their - τους (tous)- sounds like too-ss
is - είναι (eínai) - Sounds like EE-nay
tall - ψηλό (psiló) - Sounds like ps-ee-LOH
So all together Το αυτοκίνητό τους είναι ψηλό (To aftokínitó tous eínai psiló) sounds like toh ah-f-toh-KEE-nee-TOH too-ss EE-nay ps-ee-LOH.
(from: wikipedia - center for the greek language)
ASL: Their car is tall
Italian: La loro auto è alto
German: Ihr Auto ist groß
Spanish: Su coche es alto
French: Leur voiture est haut