Can I get notifications when a comment is left on an attached Trello card?

[Hilary John]

We are wanting to set up a board for our client to use so we can stream line our comms with them. 

The idea is to create duplicate cards, one for the client on their board and one for studio on our internal board. We then will attach the clients card to our internal studio card.

But is there a way to get notified on our card/through our board when the client leaves a comment or adds an attachment to their card. Or is there a way that their comments can come through into the comments section of our internal studio card?

Just want to have one way comment sharing as don't want the client to be bothered with our internal updates.

[Torben_trello]

In general, you will be notified of changes in a card (such as comments) if you are a member of the card or if you are watching the card (or list or even entire board)

You can read more about that here: http://help.trello.com/article/793-receiving-trello-notifications

Keeping cards on different boards in sync is not available natively but there are 3rd party solutions that can help with that, such as:

Cardsync
Unito
Board Sync by Unito

We recently launched an article on our blog where we explained how to connect boards together to achieve a more flexible workflow too: https://blog.trello.com/using-multiple-boards-for-a-super-flexible-workflow

Hope that helps.