Font family changes are done with:
\textrm{...} \textsf{...} \texttt{...}
Font series (weight/width) are changed with:
\textbf{...} \textmedium{...}
The font shape is changed with:
\textit{..} \textsl{..} \textsc{..}
Finally emphasis can be expressed with
\emph{..}
All such commands take care of any necessary italic correction (||). In case you want to suppress this extra space you can use
\nocorrjust before the || command or just before the closing brace, to
The above commands are also available as a separate style option |nffntcmd|. This option relies only on primitives and thus can be used with other macro packages such as plain TEX, LATEX without NFSS, etc.