Make up four sets of flash cards, each set containing three synonyms--for example, "bad," "awful" and "horrible." Instruct your student to group the synonyms together, using his dictionary or thesaurus. Pronounce each set for him and ask him to repeat. Choose one set for her to practice writing sentences. Check her sentences and correct them, incorporating nuances of the language. Repeat this project to "grow" the student's vocabulary.
Graduated reading is the key to improving the reading level. A good reading teacher can help you find a series of books that "graduate" in difficulty. Start with teachers' reading lists in the lower grades and build a list of books to read over time. Test your student's comprehension with discussions about the book. Note and praise his progress. Consistent reading in books that get harder gradually will significantly improve your ESL student's reading ability.
Write your student a friendly letter, modeling transitions and paragraph organization. Once you have taught her the parts of a friendly letter, have her write you back. Give immediate feedback. Encourage her to use a variety of types of sentences. Ask a fellow American student to write to him and have him answer. Follow with a business letter that addresses a problem. Not only will you gradually build writing skills, but you'll equip your student with real-life skills in letter writing. The key here, as with all the exercises, is to gradually "grow" your student's skills.