The underlined words below, which function as adjectives, should really be hyphenated , shouldn't they?

The underlined words below, which function as adjectives, should really be hyphenated , shouldn't they? How about in the sentence My five-year-old brother often asks me what love letter-writing is in which 'letter-writing' is a noun? Should 'letter-writing' also be hyphenated?

2. Miss Peterson is my new English-language teacher.

3. What new English-language lessons have you learned?

4. Mrs. Halligan has told as to work on another English-language activity.

5. Tommy is a high-school student, while his sister Tricia is a grade-school pupil.