English Language and Linguistics by Ibrar

Digraph and Trigraph:
Digraph:Digraph is a single sound represented by two letters.
e.g,Ch_Chair
Sh_Shoe etc.
Trigraph:Trigraph is a single sound represented by three letters.
e.g,Sch_School
Squ_Square etc.

(1)Synonymy:
Those forms of words which are closely related to each other in their meanings,then this relationship is called synonymy.
e.g,big-huge
wide-broad
Cosy-comfortable etc.
(2)Antonymy:
Those forms of words which are opposite in their meanings,then the difference is called antonymy.
e.g,big-small
Long-short
Light-heavy etc.