The following article contains brief about Prefixes in Sanskrit which is explained with the help of examples even can be used for class 9/10 or school and or college level studies.
उपसर्गेण धात्वर्थो बलादन्यत्र नीयते |प्रहार – आहार – संहार – विहार – परिहारवत् ||
धात्वर्थं बाधते कश्चित् कश्चित्तमनुवर्तते |तमेव विशिनष्टयन्यः उपसर्गगतिस्त्रिधा ||
1.When certain उपसर्ग-s are added to certain roots, we get exactly the opposite meaning
2.The meaning of the roots is enhanced due to the उपसर्ग-s
3.Some roots change their पद-s because of the उपसर्ग-s (if the root is originally PP, due to addition of certain उपसर्ग it becomes AP and vice versa)