When you add ( إنَّ ) to the sentence , it gives a confirmation in the meaning and change some grammar in the sentence It is some thing like : هو يكتب = He writes إنه يكتب =Indeed he writes , plus the change in the grammar إن خالد يكتب = Indeed Khaled writes , plus the change in the grammar Simple notification which brother Saqib mentioned it also ( A small point but يكتب = he writes. هو يقرأ = he reads. )

"هو يكتب" Is more appropriate in a normal context. "انه يكتب" When you answer a qestion like - ماذا يفعل أحمد؟ - انه يكتب Or you can put it in a normal context if you have the subject like "إن أحمد يكتب" ------------------------------ As for your qestion what does "انه" mean? "إن" is just a letter that has a confirmative function "ه" is pronoun refers to a masculine subject If it was a feminine subject, the pronoun will be "ها" Together "إنها" ------------------------ SO.. Why do we put "إن" in a context? You know that in languages there are verbal and nominal sentences. Arabic is a verbal sentences language. We start the sentence with verbs not subjects like يتكلم خالد العربية تذهب هند إلى لمدرسة But if we put "إن", it turns the sentence to nominal one like إن خالد يتكلم العربية إن هند تذهب إلى المدرسة ---------------------------------- Hope this is helping

A small point but يكتب = he writes. هو يقرأ = he reads.

A very good question!