1. She has a ponytail.

2. She has pigtails.
3. She has braids.
4. She has long curved hair.
5. She has short wavy hair.
6. He has medioum-length straight hair.
7. He has average-length curved blond hair.

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Are the expressions above grammatical? Would you check the expressions which are not appropriate.

Instead of "curved", we normally used "wavy". Be sure to used commas between a group of adjectives. Example - He has average-length, wavy, blond hair.

To check whether the expressions are grammatical, we need to analyze each sentence individually:

1. "She has a ponytail." – This sentence is grammatically correct.

2. "She has pigtails." – This sentence is grammatically correct.

3. "She has braids." – This sentence is grammatically correct.

4. "She has long curved hair." – This sentence is not grammatically correct. The correct form would be "She has long, curved hair." The comma is necessary to separate the adjectives "long" and "curved."

5. "She has short wavy hair." – This sentence is grammatically correct.

6. "He has medioum-length straight hair." – This sentence is not grammatically correct. The correct form would be "He has medium-length straight hair." The misspelling of "medium" is corrected, and a hyphen is inserted between "medium" and "length."

7. "He has average-length curved blond hair." – This sentence is grammatically correct.

So, sentences 4 and 6 are not appropriate and have been corrected above.