Beside having the option to manually enter a culture for the search query or search suggestions query (e.g. 1033 for 'en-US'), add a ComboBox with the different languages which support linguistic features to select from, according to:
Linguistic search features in SharePoint Server 2013
https://technet.microsoft.com/en-us/library/jj219499.aspx
Linguistic search features in SharePoint Server 2016
https://technet.microsoft.com/en-us/library/jj219499(v=office.16).aspx
These are the available languages you can select from:
Afrikaans [af | 54]
Albanian [sq | 28]
Arabic [ar | 1] supports: word breaking / stemming
Armenian [hy | 43]
Azerbaijani [az | 44]
Bangla [bn | 69] supports: word breaking / stemming
Basque (Basque) [eu | 45]
Belarusian [be | 35]
Bosnian [bs | 30746]
Breton [br | 126]
Bulgarian [bg | 2] supports: word breaking / stemming
Catalan [ca | 3] supports: word breaking / stemming
Chinese Simplified [zh-cn | 2052] supports: word breaking
Chinese Traditional [zh-tw | 1028] supports: word breaking
Croatian [hr | 26] supports: word breaking / stemming
Czech [cs | 5] supports: word breaking / stemming
Danish [da | 6] supports: word breaking / stemming / decompounding
Dutch [nl | 19] supports: word breaking / stemming / decompounding / phonetic
English [en | 9] supports: word breaking / stemming / phonetic
Estonian [et | 37] supports: word breaking / stemming
Faeroese [fo | 56]
Farsi [fa | 41]
Filipino [fil | 100]
Finnish [fi | 11] supports: word breaking / stemming / decompounding
French [fr | 12] supports: word breaking / stemming / phonetic
Frisian [fy | 98]
Galician [gl | 86]
Georgian [ka | 55]
German [de | 7] supports: word breaking / stemming / decompounding / phonetic
Greek [el | 8] supports: word breaking / stemming
Gujarati [gu | 71] supports: word breaking / stemming
Hausa [ha | 104]
Hebrew [he | 13] supports: word breaking / stemming
Hindi [hi | 57] supports: word breaking / stemming
Hungarian [hu | 14] supports: word breaking / stemming
Icelandic [is | 15] supports: word breaking / stemming
Indonesian [id | 33] supports: word breaking / stemming
Irish Gaelic [ga | 60]
Italian [it | 16] supports: word breaking / stemming / phonetic
Japanese [ja | 17] supports: word breaking / phonetic
Kannada [kn | 75] supports: word breaking / stemming
Kazakh [kk | 63]
Kirghiz [ky | 64]
Korean [ko | 18] supports: word breaking / stemming
Kurdish [ku | 146]
Latvian [lv | 38] supports: word breaking / stemming
Lithuanian [lt | 39] supports: word breaking / stemming
Luxembourgish [lb | 110]
Macedonian [mk | 47]
Malay [ms | 62] supports: word breaking / stemming
Malayalam [ml | 76] supports: word breaking / stemming
Maltese [mt | 58]
Maori [mi | 129]
Marathi [mr | 78] supports: word breaking / stemming
Mongolian [mn | 80]
Norwegian Bokmål [nb | 31764] supports: word breaking / stemming / decompounding
Norwegian Nynorsk [nn | 30740] supports: stemming
Pashto [ps | 99]
Polish [pl | 21] supports: word breaking / stemming / phonetic
Portuguese [pt | 22] supports: word breaking / stemming / phonetic
Punjabi [pa | 70] supports: word breaking / stemming
Romanian [ro | 24] supports: word breaking / stemming
Romansh [rm | 23]
Russian [ru | 25] supports: word breaking / stemming / phonetic
Sami Nothern [se | 59]
Serbian [sr | 31770] supports: word breaking / stemming
Slovak [sk | 27] supports: word breaking / stemming
Slovenian [sl | 36] supports: word breaking / stemming
Spanish [es | 10] supports: word breaking / stemming / phonetic
Swahili [sw | 65]
Swedish [sv | 29] supports: word breaking / stemming / decompounding
Tamil [ta | 73] supports: word breaking / stemming
Telugu [te | 74] supports: word breaking / stemming
Thai [th | 30] supports: word breaking
Turkish [tr | 31] supports: word breaking / stemming
Ukrainian [uk | 34] supports: word breaking / stemming
Urdu [ur | 32] supports: word breaking / stemming
Uzbek [uz | 67]
Vietnamese [vi | 42] supports: word breaking
Welsh [cy | 82]
Zulu [zu | 53]
Comments: Resolved with changeset 31857: Changed TextBox to ComboBox for Culture / SuggestionsCulture
Linguistic search features in SharePoint Server 2013
https://technet.microsoft.com/en-us/library/jj219499.aspx
Linguistic search features in SharePoint Server 2016
https://technet.microsoft.com/en-us/library/jj219499(v=office.16).aspx
These are the available languages you can select from:
Afrikaans [af | 54]
Albanian [sq | 28]
Arabic [ar | 1] supports: word breaking / stemming
Armenian [hy | 43]
Azerbaijani [az | 44]
Bangla [bn | 69] supports: word breaking / stemming
Basque (Basque) [eu | 45]
Belarusian [be | 35]
Bosnian [bs | 30746]
Breton [br | 126]
Bulgarian [bg | 2] supports: word breaking / stemming
Catalan [ca | 3] supports: word breaking / stemming
Chinese Simplified [zh-cn | 2052] supports: word breaking
Chinese Traditional [zh-tw | 1028] supports: word breaking
Croatian [hr | 26] supports: word breaking / stemming
Czech [cs | 5] supports: word breaking / stemming
Danish [da | 6] supports: word breaking / stemming / decompounding
Dutch [nl | 19] supports: word breaking / stemming / decompounding / phonetic
English [en | 9] supports: word breaking / stemming / phonetic
Estonian [et | 37] supports: word breaking / stemming
Faeroese [fo | 56]
Farsi [fa | 41]
Filipino [fil | 100]
Finnish [fi | 11] supports: word breaking / stemming / decompounding
French [fr | 12] supports: word breaking / stemming / phonetic
Frisian [fy | 98]
Galician [gl | 86]
Georgian [ka | 55]
German [de | 7] supports: word breaking / stemming / decompounding / phonetic
Greek [el | 8] supports: word breaking / stemming
Gujarati [gu | 71] supports: word breaking / stemming
Hausa [ha | 104]
Hebrew [he | 13] supports: word breaking / stemming
Hindi [hi | 57] supports: word breaking / stemming
Hungarian [hu | 14] supports: word breaking / stemming
Icelandic [is | 15] supports: word breaking / stemming
Indonesian [id | 33] supports: word breaking / stemming
Irish Gaelic [ga | 60]
Italian [it | 16] supports: word breaking / stemming / phonetic
Japanese [ja | 17] supports: word breaking / phonetic
Kannada [kn | 75] supports: word breaking / stemming
Kazakh [kk | 63]
Kirghiz [ky | 64]
Korean [ko | 18] supports: word breaking / stemming
Kurdish [ku | 146]
Latvian [lv | 38] supports: word breaking / stemming
Lithuanian [lt | 39] supports: word breaking / stemming
Luxembourgish [lb | 110]
Macedonian [mk | 47]
Malay [ms | 62] supports: word breaking / stemming
Malayalam [ml | 76] supports: word breaking / stemming
Maltese [mt | 58]
Maori [mi | 129]
Marathi [mr | 78] supports: word breaking / stemming
Mongolian [mn | 80]
Norwegian Bokmål [nb | 31764] supports: word breaking / stemming / decompounding
Norwegian Nynorsk [nn | 30740] supports: stemming
Pashto [ps | 99]
Polish [pl | 21] supports: word breaking / stemming / phonetic
Portuguese [pt | 22] supports: word breaking / stemming / phonetic
Punjabi [pa | 70] supports: word breaking / stemming
Romanian [ro | 24] supports: word breaking / stemming
Romansh [rm | 23]
Russian [ru | 25] supports: word breaking / stemming / phonetic
Sami Nothern [se | 59]
Serbian [sr | 31770] supports: word breaking / stemming
Slovak [sk | 27] supports: word breaking / stemming
Slovenian [sl | 36] supports: word breaking / stemming
Spanish [es | 10] supports: word breaking / stemming / phonetic
Swahili [sw | 65]
Swedish [sv | 29] supports: word breaking / stemming / decompounding
Tamil [ta | 73] supports: word breaking / stemming
Telugu [te | 74] supports: word breaking / stemming
Thai [th | 30] supports: word breaking
Turkish [tr | 31] supports: word breaking / stemming
Ukrainian [uk | 34] supports: word breaking / stemming
Urdu [ur | 32] supports: word breaking / stemming
Uzbek [uz | 67]
Vietnamese [vi | 42] supports: word breaking
Welsh [cy | 82]
Zulu [zu | 53]
Comments: Resolved with changeset 31857: Changed TextBox to ComboBox for Culture / SuggestionsCulture