Forth - fourth
- The word for 4th is spelled fourth - like the number 4, four.
- The word forth is NOT a number. It is a slightly old-fashioned adverb, meaning roughly 'forwards' or 'out', both literally and figuratively. "The captain paced back and forth over the narrow deck, considering his plans", "Back and forth they went, covering the same old ground, arguing over the same old disagreements", or "The knight went forth to battle in a suit of armour".
- There is also a proper noun naming a river Forth in Scotland. It ends in the wide estuary near which Edinburgh stands known as the Firth of Forth. The Firth is spanned by the famous Forth Bridge (of which there is only one) and the Forth Road Bridge (which is the second crossing in that area).
In 2011, construction began on the Queensferry Crossing, a second road bridge across the Forth in the vicinity of Queensferry, the small town which serves as the jumping-off point on the south bank for both existing bridges. The new bridge was necessary because the Road Bridge was experiencing far higher traffic than expected and had developed structural faults which will shorten its planned life. The Queensferry Crossing opened in August, 2017.