How does the location of stress distinguish a compound noun from

How does the location of stress distinguish a compound noun from a phrase consisting of the same elements? You can explain with examples.
【正确答案】：i. Semantic features
When two or more free morphemes are combined into a compound, a new meaning arise, which is in most cases no longer a simple combination of the meanings of the component elements.
E.g. a greenhouse, a dark horse
ii. Orthographic features
Most compound words are either hyphenated or completed joined, like day-care, grasshopper. But this is not an exclusive practice, for some compound words are always written separately, like day school, sports car, Sunday best
iii. The stress of a compound usually falls on the first constituent morpheme.
Compare:
Compound: 'greenhouse, 'blackboard
Free noun phrase: green 'house, black 'board
iv. Grammatical features
Compound words have their own grammatical features. They have special internal structures, which are normally unacceptable in free phrases, e.g.
v. +n.→n.: cut-throat, breakwater
n. + -ed→adj.: homemade, book-learned
adj. +-ed→adj.: newborn, deep-laid
V. Compounds have special morphological features. Their adjectives constituents normally do not take the comparative and superlative forms.
fine arts-finer arts-finest arts
loudspeaker-louder speaker