Adjectives and Adverbs: Position in Expressions of Measurement

Typical mistake: Everest is high 9,000 meters. 

In expressions of measurement, the adjective or adverb comes after the measurement-noun. 

Examples: 

Six feet high    Ten feet down    ten years old    Two miles long    Six feet deep

Notice the difference between ten feet square (= 10 ft x 10 ft) and ten square feet (= 2 ft x 5 ft, or 10 ft x 1 ft). 

When expressions like these are used as attributive adjectives (before the noun), the measurement noun is normally singular: Compare the following: a bole six feet deep     Vs     a six-foot-deep bole