How to Use "Acres" versus "Hectares"
An acre is a unit of land measurement in the imperial system, primarily used in the United States, and it is equivalent to approximately 4,047 square meters.
A hectare is a unit of land measurement in the metric system, widely used globally, and is equal to 10,000 square meters.
How to Use "Years Old" vs. "Year Old" vs. "Year-Old"
"Years old" is a phrase used to indicate the age of a person or thing. When it comes after the noun it modifies, we don't use a hyphen. "Year-old" also indicates the age of a person or thing, but we use a hyphen when it comes before the noun it modifies or if it acts as a noun on its own.