N-grams for text processing

N-gram is an N sequence of words. It can be a unigram (one word), bigram (sequence of two words), trigram (sequence of three words), and so on. It focuses on a sequence of words. Such a method is very useful in speech recognition and predicting input text. It helps us to predict the next words that could occur in a given sequence. Search engines also use the n-gram technique to predict the next word while a search query is typed in a search bar. 

Let us consider a sentence: 

“This is going to be an amazing experience.”

Unigram for the above sentence can be written as:

• "This"
• "is"
• "going"
• "to"
• "be"
• "an"
• "amazing"
• "experience"

Bigram for the above sentence can be written as:

• “This is”
• “is going”
• “going to”
• "to be"
• "be an"
• "an amazing"
• "amazing experience"

Trigram for the above sentence can be written as:

• "This is going"
• "is going to "
• "going to be"
• "to be an"
• "be an amazing"
• "an amazing experience"

With n-grams, we can use a bag of n-grams (for example, a bag of bigrams) instead of only using a bag of words. A bag of bigrams or trigrams is more powerful than using just a bag of words as it takes the context into consideration as well.