MySQL join with where clause

I have two tables I want to join.

I want all of the categories in the categories table and also all of the categories subscribed to by a user in the category_subscriptions table.

essentially this is my query so far:

SELECT *
FROM categories
LEFT JOIN user_category_subscriptions 
     ON user_category_subscriptions.category_id = categories.category_id

This works fine however I want to add a where clause on the end of the query which then essentially makes it an inner/equi join.

   SELECT *
    FROM categories
    LEFT JOIN user_category_subscriptions 
         ON user_category_subscriptions.category_id = categories.category_id 
   WHERE user_category_subscriptions.user_id = 1

How do I get all the categories as well as all the categories subscribed to by a particular user using only one query?

category_id being a key in both categories table and user_category_subscriptions. user_id residing in the user_category_subscriptions table.

thanks