Grollige.com doesn't currently have the level of resources enjoyed by the likes
of Google, MicroSoft and DuckDuckGo.
It particularly lacks any Natural Language Processing capability, so you have to search for key words rather than ask questions.
Until such time as NLP is included, Grollige doesn't have the ability to analyse complex word structures.
Here are some suggestions on how you might currently get better search results on Grollige:
Also, Grollige doesn't yet support 'AND', 'OR', 'SITE:' or other features.
In future, if enough people decide to support Grollige financially (hint!) then this problem can be overcome. All things are possible, they just require resources.