Which package must you include to use the italics command \textit{}?
More generally, if I find a command I would like to use (in a tutorial, for example), how can I easily identify which package I must include to use the command?
\textit, \textrm, \textbf and \textsf are the primitive commands in LaTeX, these tags never expect any packages, if you need any text should be in bold with italic face, then should use the tag as \textbf{\textit{...}}... Hope this may helpful to you...
https://www.tutorialspoint.com/tex_commands/textit.htm may helps you...
\textit. Your more general question was asked earlier, so perhaps you can find some useful info in https://tex.stackexchange.com/questions/3777 – Torbjørn T. Jun 18 '19 at 19:24\textitcommand:\documentclass{article} \begin{document} text \textit{italic text} \end{document}– leandriis Jun 18 '19 at 20:01\textit{}but\emph{}that have a semantic meaning instead of a formatting meaning ("text to be emphasized" instead of "text to be italized"). It seems a bit stupid because the method of emphasizing is use italics, , but note that\textit{l\textit{l}l}will produce simply " lll " whereas\emph{l\emph{l}l}will produce " lll " (i.e, emphasized upright text within and already emphasized text with italics) which could have sense in some contexts. Moreover, one ot them should not be redefined, guess which one? – Fran Apr 14 '20 at 09:40