Extract n words from string : i have a text containing sentences in each line, and in front of each word its lemmetize form exemple:
he "he" went "go" to "to" school "school" with "with" his "his" freinds "freind"  
i would like to extract for example three by three word in in each line. The result seems like this:

he "he" went "go" to "to" \n
went "go" to "to" school "school" \n
to "to" school "school" with "with" \n
school "school" with "with" his "his" \n
with "with" his "his" freinds "freind" \n

Please, have you any idea to do this, many thanks,

