\documentclass{article}

\begin{document}

\textit {\textbf {This is bold-italic, but it looks italic}}
\textbf{\textit{This is bold-italic, but it looks italic}}
\textbf{\textbf{This is bold-italic, but it looks italic}}
\textbf{\emph{This is bold-italic, but it looks italic}}
\textit{\emph{This is bold-italic, but it looks italic}}
\emph{\textbf{This is bold-italic, but it looks italic}}

\end{document}
