```r
bigrams_united <- bigrams_filtered %>%
  unite(bigram, word1, word2, sep = " ")

bigrams_united
```

```
## # A tibble: 44,784 x 2
##    book                bigram                  
##    <fct>               <chr>                   
##  1 Sense & Sensibility jane austen             
##  2 Sense & Sensibility austen 1811             
##  3 Sense & Sensibility 1811 chapter            
##  4 Sense & Sensibility chapter 1               
##  5 Sense & Sensibility norland park            
##  6 Sense & Sensibility surrounding acquaintance
##  7 Sense & Sensibility late owner              
##  8 Sense & Sensibility advanced age            
##  9 Sense & Sensibility constant companion      
## 10 Sense & Sensibility happened ten            
## # … with 44,774 more rows
```