It's not just a custom dictionary. Stop words are usually excluded for a reason, you need to understand the nature of the query, and when to exclude what looks

It's not just a custom dictionary. Stop words are usually excluded for a reason, you need to understand the nature of the query, and when to exclude what looks like stop words from being pruned. It's not really a job for a snowball stemmer, as you do need to operate over multiple tokens to gather context.