Found this on Google and have 're-tweeted' the gist of it here. NB When using an 'operator', don't add any spaces between the operator and your query.
- Search for an exact word or phrase eg "search query"
- Exclude a word eg -word You can also exclude results based on other operators, like excluding all results from a specific site.
- Search within a site or domain eg site:domain.org You can also search within a specific top-level domain eg site:.co.uk
- Search for pages that link to a URL eg link:query You can also search for links to specific pages, eg link:google.com/images
- Search for pages that are similar to a URL: eg related:query
- Include a "fill in the blank": eg query * query an asterisk in a query is a placeholder for any unknown or wildcard terms
- Search for either word: eg query OR query NB CAPS world cup location 2014 OR 2018
- Search for a number range: eg number..number
- Complex queries: eg (google +yahoo) OR (google +bing) +compare