Problem with using gb4e export of linguistic examples & unicode

Question

I am new to LaTex - total rookie here, sorry if I'm not saying things properly lol! - and I am facing some problems with it. I am working with a web-based program called Dative for linguistic analysis and interlinearization. This program gives the option of exporting glossed examples in various Tex formats, such as ExPex, gb4e and Convington. The problem is that when I try to paste and compile an example in my TexStudio document, when I compile the following error message pops up:

Package inputenc Error: Unicode character ə (U+0259)(inputenc) not set up for use with LaTeX. ...g l-assēfərnə ... rāyḥāt Ḥand//

This is for the character /ə/, but this happens with any non-standard character which I do a great use of in my work, obviously. What am I doing wrong? The code is pasted below. Thank you for your help!

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{gb4e}

\begin{document}
\begin{exe}
    \ex
        \glll wə-hes nētaḥ Warx ġabōr dənāwəg l-assēfərnə ... rāyḥāt Ḥand\\
        wə=hes nētaḥ Warx ġabōr dənāwəg l=assēfər-nə \# rāyḥ-āt Ḥand\\
        CONN=when go\_down\textbackslash{}PFV.3S.M Warx encounter\textbackslash{}PFV.3S.M boat\textbackslash{}PL REL=travel\textbackslash{}PFV-3PL.F \# go(AD)\textbackslash{}PTCP-PL.F India\\
        \trans `And when he went down to Warx. (on one occasion) he came across wooden boats going along... they were going to India.'
\end{exe}
\end{document}

Answer 1

With this kind of Unicode input it is (much) easier to use one of the two Unicode engines, i.e., XeLaTeX or LuaLaTeX (and not pdfLaTeX), and select a font that contains these characters.

Example with XeLaTeX and DejaVu Serif as font:

\documentclass{article}
\usepackage{fontspec}
\setmainfont{DejaVu Serif}
\usepackage{gb4e}

\begin{document}
\begin{exe}
    \ex
        \glll wə-hes nētaḥ Warx ġabōr dənāwəg l-assēfərnə ... rāyḥāt Ḥand\\
        wə=hes nētaḥ Warx ġabōr dənāwəg l=assēfər-nə \# rāyḥ-āt Ḥand\\
        CONN=when go\_down\textbackslash{}PFV.3S.M Warx encounter\textbackslash{}PFV.3S.M boat\textbackslash{}PL REL=travel\textbackslash{}PFV-3PL.F \# go(AD)\textbackslash{}PTCP-PL.F India\\
        \trans `And when he went down to Warx. (on one occasion) he came across wooden boats going along... they were going to India.'
\end{exe}
\end{document}

Result: