This page provides guidance for some of the basic principles and practices of writing calculations or logic in CommCare
Single vs Double Quotations
Generally XPath expressions values in display or calculation conditions will be surrounded by inside quotes IE
<bind nodeset="/data/name" />
However literal values would also be surrounded by single quotes:
<bind nodeset="/data/name" calculate="'will pride'" />
...
You can use single quotes or double quotes, both work fine.
Spaces
Spaces generally will not matter (i.e. Will be ignored) unless they are themselves in a string literal
References
xform details: http://dimagi.github.io/xform-spec/#xpath-pathsinside quotes.