"Philadelphia is a city."
Translation:Philadelphia est urbs.
est should be at the end of the sentence, but also word order is very fluid and should not count against students
Word order should not matter; verbs usually are placed at the end of the sentence
The above comments are correct. In Classical Latin you typically see verbs at the end of the sentence, but given the inflective nature of the language word order should not matter.
As with other posters: I was marked wrong for placing 'est' at the end of the city, but word order is unimportant in Latin and it flows better with the verb at the end. There's a wee glitch.