You can't.

MS stopped support in 2005 for Internet Explorer.

Spelling dictionaries for Internet Explorer 11 Release Preview. Internet Explorer 11 Release Preview brings the 'best in class' spelling engine and dictionaries used by Microsoft to the browser. Internet Explorer 11 Release Preview also supports autocorrection or 'correction-while-you-type'. CNET Download provides free downloads for Windows, Mac, iOS and Android devices across all categories of software and apps, including security, utilities, games, video and browsers.

If you were running a virtual machine with Windows could you download Explorer for your Mac.

If you are looking for browsers for the Mac besides Safari, consider Firefox, Brave, Opera, or Sea Monkey.

Download Internet Explorer For Apple Mac

Internet Explorer For Mac Download

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Internet Explorer 11 For Mac Download 2019

If you are trying to reach a particular website that calls for IE, go into Preferences in Safari, go to Develop menu, select User Agent and select Internet Explorer 11. See if the website that you are trying to reach handles that.