Using Hints and Substitute to enhance recognition of words

I’m also trying to use hinting and substitution methods to rectify errors and improve recognition. I’m using deep speech model only as ASR. I’ve used deep speech 2 model to build my own pbm and scorer as I’m trying to improvise the ASR for Hindi language. I’m facing issues like while saying “Haa”, the model is only catching “a”. Need to rectify that, can you please suggest how can I implement ‘hints’ or ‘substitution’ for that.