QUICK ANSWER
"What is that?" is a phrase which is often translated as "¿Qué es eso?", and "their" is an adjective which is often translated as "su". Learn more about the difference between "What is that?" and "their" below.
What is that?(
wuht
 
ihz
 
thaht
)
A phrase is a group of words commonly used together (e.g once upon a time).
phrase
1. (general)
a. ¿Qué es eso?
"What is that?" she asked, pointing to a flashing light on the control panel."¿Qué es eso?" preguntó, señalando una luz intermitente en el tablero de control.
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their(
thehr
)
An adjective is a word that describes a noun (e.g. the big dog).
adjective
1. (possessive)
a. su (singular)
I admire their attitude.Admiro su actitud.
b. sus (plural)
Their children behaved beautifully.Sus hijos se portaron de maravilla.
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