Update gensim word2vec model

Question

I have a word2vec model in gensim trained over 98892 documents. For any given sentence that is not present in the sentences array (i.e. the set over which I trained the mode

Answer 1

1. train() expects a sequence of sentences on input, not one sentence.

2. train() only updates weights for existing feature vectors based on existing vocabulary. You cannot add new vocabulary (=new feature vectors) using train().