Bigram
A bigram or digram is every sequence of two adjacent elements in a string of tokens, which are typically letters, syllables, or words; they are n-grams for n=2. The frequency distribution of bigrams in a string are commonly used for simple statistical analysis of text in many applications, including in computational linguistics, cryptography, speech recognition, and so on.
Gappy bigrams or skipping bigrams are word pairs which allow gaps (perhaps avoiding connecting words, or allowing some simulation of dependencies, as in a dependency grammar).
Head word bigrams are gappy bigrams with an explicit dependency relationship.
Bigrams help provide the conditional probability of a token given the preceding token, when the relation of the conditional probability is applied:
That is, the probability 
of a token 
given the preceding token 
is equal to the probability of their bigram, or the co-occurrence of the two tokens 
, divided by the probability of the preceding token.
Applications
Bigrams are used in one of the most successful language models for speech recognition. They are a special case of N-gram.
Podcasts:
-
by Paku Romi
Tensai (reincarnation)
by: Paku Romi(Japanese)
Sougon na tsuki no shita wo aruite
Mienai asu wo sagasu tabibito
Toki ni mayoi toki ni aseri
Toki ni taore sou ni natte
Eien ni tsuzuku you na michi
Ashimoto yureru hana ni
Yorokobi ga saite iru
Douka miotosa nai de
Chiisana ai no shirushi wo
Hoshi ga umareru you ni
Meguru inochi no fushigi
Watashi wa anata no naka de
Itsumo iki wo shite iru kara
Chikara no kagiri tatakau sugata
Kanashimi no wake wo tadoru tabibito
Toki ni nayami toki ni kizutsuki
Toki ni uragirare tari shite
Kewashiku tachifusagaru kabe
Daichi wo hashiru kaze ni
Yasashisa ga yadotteru
Douka mimi wo sumashite
Sasayaku ai no kotoba ni
Kisetsu ga kawaru you ni
Meguru inochi no fushigi
Watashi wa anata no koto wo
Itsumo mimamotte iru kara
Ashimoto yureru hana ni
Yorokobi ga saite iru
Douka miotosanai de
Chiisana ai no shirushi wo
Asa ga mezameru you ni
Meguru inochi no fushigi
Watashi wa anata no naka de
Itsumo iki wo shite iru kara
(English)
Walking under a solemn moon
A traveler searching for an unseen tomorrow
At times confused, at times impatient
at times seeming about to collapse
A path that seems to continue for eternity
In the flowers swaying beside my feet
joy is blooming
Please don't overlook
the small signs of love
The mystery of a life that returns,
like the way a star is born...
Because I am always breathing,
within you.
The form of one fighting, at the limits of their strength
A traveler pursuing the reason for sadness
At time worried, at times wounded,
at times being betrayed
A steep wall blocking the way
In the wind that runs through the earth
gentleness is dwelling
Please try and hear
the whispered words of love
The mystery of a life that returns,
like the way the seasons change...
Because I am always watching over you.
In the flowers swaying beside my feet
joy is blooming
Please don't overlook
the small signs of love
The mystery of a life that returns,
like the way the morning awakens...
Because I am always breathing,