Hi Appu,

The verb 'aller' needs to be conjugated in the present tense and followed by the infinitive of the thing you are going to do. So, 'je vais écrire' is correct here and the pattern is 'tu vas écrire', 'il va écrire' and so on.

Hope this helps :-) 

Am new here, although the questions is a year ago, i think am begin to understand the Futur Proche which is Future tense....my brother don't be confused you are using two verbs in these sentences make sure you conjugate the first verb and leave the other  verb (infinitive) ok,  for example I am going to write note we have two verbs there which is going (aller) to Go....Write(écrire) to write please conjugate the first verb and leave the other verb infinitive ok,  je vais écrire à mon frère cet après-midi, remember still in future not doing it now it's  later it will be  je vais écrire à mon frère cet après-midi, when two verbs are in a sentence one will be conjugated the other verb will remain like that in the sentence. 

Am new here, although the questions is a year ago, i think am begin to understand the Futur Proche which is Future tense....my brother don't be confused you are using two verbs in these sentences make sure you conjugate the first verb and leave the other  verb (infinitive) ok,  for example I am going to write note we have two verbs there which is going (aller) to Go....Write(écrire) to write please conjugate the first verb and leave the other verb infinitive ok,  je vais écrire à mon frère cet après-midi, remember still in future not doing it now it's  later it will be  je vais écrire à mon frère cet après-midi, when two verbs are in a sentence one will be conjugated the other verb will remain like that in the sentence.