Does Magento 2 Search Autocomplete Support Multi-Language?

Yes, Magento 2 search autocomplete is compatible with multilingual websites. It can show suggestions in the store's default language and other supported languages. Magento 2 search autocomplete gives global users a local search experience. This increases user engagement. You can make separate customizations for each language from the admin panel. Shoppers get relevant results in their language. This feature also proves to be very effective for multi-store setups.

Check out more details at: http://webkul.com/blog/magento2-search-suggestion/