I'd like to use the sentence case (without editing the bib file!) for journal articles with biblatex-chicago but don't know how. So far, \MakeSentenceCase* looks promising to me, but it fails to change the cases for me. I use lualatex + biber on texlive 2020 on macOS Big Sur. A self-contained example is below.
\begin{filecontents}[overwrite]{tmp-refs.bib}
@article{paper:Title-Case,
title = {Title-Cased Title {ABC} DEF Hij},
author = {Author Aaa and Author Bbb},
year = {1986},
volume = {16},
pages = {1929-1943},
journal = {Journal of Something}
}
@article{paper:Sentence-case,
title = {Sentence-cased title {ABC} DEF Hij},
author = {Author Ccc and Author Ddd},
year = {1987},
volume = {17},
pages = {1943-1949},
journal = {Journal of Something Else}
}
@book{book:Title-Case,
title = {Title-Cased Book Title {ABC} DEF Hij},
author = {Author Eee},
year = {1988},
pages = {123},
publisher = {A Good Publisher}
}
@book{book:Sentence-case,
title = {Sentence-cased book {ABC} DEF Hij},
author = {Author Fff},
year = {1989},
pages = {567},
publisher = {Another Good Publisher}
}
\end{filecontents}
\documentclass[11pt,a4paper]{article}
\usepackage[authordate,backend=biber]{biblatex-chicago}
\bibliography{tmp-refs}
\DeclareFieldFormat{titlecase}{\MakeSentenceCase{#1}}
%\DeclareFieldFormat{titlecase:title}{\MakeSentenceCase{#1}}
\begin{document}
\autocite{paper:Title-Case}
\autocite{paper:Sentence-case}
\autocite{book:Title-Case}
\autocite{book:Sentence-case}
\printbibliography
\end{document}
