R
!!!ngram
{{pre
install.packages("ngram")
library(ngram)
> sample <- "I often hear that death penalty is reasonable for people whose family member or friend is killed by someone."
> get.ngrams(ngram(sample))
 [1] "death penalty"  "is reasonable"  "hear that"      "friend is"      "is killed"      "for people"     "whose family"  
 [8] "by someone."    "often hear"     "people whose"   "that death"     "killed by"      "I often"        "member or"     
[15] "or friend"      "family member"  "reasonable for" "penalty is"    
> 
> get.ngrams(ngram(preprocess(sample, remove.punct=TRUE)))
 [1] "death penalty"  "is reasonable"  "hear that"      "friend is"      "is killed"      "i often"        "for people"    
 [8] "whose family"   "often hear"     "people whose"   "by someone"     "that death"     "killed by"      "member or"     
[15] "or friend"      "family member"  "reasonable for" "penalty is"