"The dogs are going to the office."
Translation:Köpekler ofise gidiyor.
Tips and Notes of To Be lesson says
The suffix -lAr is optional in the 3rd person pl. However, it is only optional when referring to people. This suffix may not be used for items and animals. Only humans!
But I have seen the opposite in Duolingo
Both of your examples have the same suffix: -e (hayvanat bahçesinE and ofisE). The base word is ofis.
(hayvanat bahçesi has an additional linking -n- because the case marker -e comes after a possessive ending -si, but that -n- is not really part of the suffix. If you'd have a noun ending in a vowel such as büro which also means "office", you'd also get a linking consonant, in this case -y-: büroya.)
It's the dative case of ofis, formed with the -A suffix (so -e after the front vowel ofis).
Could i say ofisye
No need to use a buffer consonant -y- to avoid two vowels next to each other, since ofis doesn't end in a vowel.
You would need it in a word such as elma : elmaya or anne : anneye.