could you please let me know the distintion between compound words and collocations ...
http://grammar.ccc.commnet.edu/grammar/compounds.htm
This webpage has a good explanation of compound words, including those that are spelled as one word each, those that are hyphenated, and those that are spelled as two words esch.
http://www.manythings.org/vocabulary/lists/a/words.php?f=compound_words
And here's a good list of compound words to start with.
http://www.englishclub.com/vocabulary/collocations.htm
Here is a really good explanation of collocations. Be sure to click on the links toward the bottom of this webpage.