In its translation the NIV adds the word “gate” to the word “sheep” and KJV adds “market” at the same place.  The reason for the additions is that “sheep” is an adjective with no apparent noun to describe.  The possible readings are the 2 mentioned and “sheep-pool” where “sheep” would describe the following noun “pool.” Market is unlikely since no mention is made anywhere in history of a sheep market and in fact, sheep were sold in the Temple at the time of Jesus.

“Bethesda” where other manuscripts have “Bethzatha” or “Bethsaida.”  Most certainly the name was Bethseda which means “house of mercy” or “flowing water.”  The word was Aramaic which would have been unfamiliar to Greek scribes copying the manuscripts and could have contributed to an error.  The location of this pool is uncertain today although many possibilities have been given.

“colonnades” is the translation of the Greek word stoa which means porticos or cloisters. They were covered colonnades where people could gather and be protected from the weather and sun.