What Grade?

There are plenty of softwares that will provide you with assistance in in your tutoring of your 9 year old brother. Most of all just take time and be patient with him and help him to the best of your ability.

If he's still in school, you may want to contact his teacher so you can see what his weakenesses are or you can look at his report card and probably determine what they are.

There are many great and FREE reading programs being offered around. You might check at your local library to see what Summer Reading Program they are offering and go into Barnes and Noble http://www.barnesandnoble.com/summer/reading.asp?&z=y&kids=y&cds2Pid=13869

Free resources:
http://www.mes-english.com/
http://www.sitesforteachers.com/ (very good)

find out if he is to be learning about adjectives, or sentence usage, or story writing. . .

There are many areas and someone has to decide. If he has another teacher to tell what is to be learned, then tutor him in those things.

If YOU are the decider, then ask him for a sample of stuff in a "explore and decide" time. Then critique it and assess where he needs help.

I think the selection of links below will help you quite a lot and I hope you both enjoy using the interactive sites.

Fourth Grade English
Note *All links below are either interactive or video clips.

http://schoolweb.missouri.edu/smithville.k12.mo.us/uptegrove/fourthgradeenglish.html

http://www.internet4classrooms.com/skills_4th_original.htm

http://www.quia.com/pages/hostetterwriting.html

http://www.usd267.com/TL%20Student%20Pages/4th5thgradelinks/45StandardizedTestinglinks.html

just type in free lesson plans and search... thousands will come up and you can narrow it down by subject, grade etc.