Hi @Wael ElKadi,
Thank you for posting in this community.Unfortunately, SharePoint doesn't record file language types, so you can't filter results by language type in search web part.
I recommend you give suggestion in the feedback portal and help to make improvements. Many features of current products are designed and upgraded based on customers’ feedback. With requirements like this increase, the problem may well be released in the future. I will vote for you.
However, if you're searching for a multilingual page, you can try this article to filter your results by language.
Search and modern multilingual pages in SharePoint Online
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