How to cover international lowercase word characters in a regex?

Question

How do I cover all lowercase non-numeric word characters in a regex?

For example this would cover Müller for german umlauts

/[A-Z][a-zäöü-]+/g

...but what about french or spanish word characters? Is it possible to get those covered by a range or something like that?

The regex should NOT match a string which has multiple uppercase characters, like DOntGetMe. But it should match McDonald.

So I came up at the end with

/([A-Z][a-zäöü'-](?:[\w'-]+)?)/g

But it still don't cover french/spanish characters.

https://regex101.com/r/ofl4tj/2

Match

Smith
Müller
McDonald
O'Riley
Lee
Li
Manco-Johnson

Don't match

MIsspelled
ABC

Answer 1

Since you are looking for a letter from English alphabet as beginning of word use a word boundary \b right before [A-Z]. Using Unicode CLDR or Mother E**, to match all lowercase letters from all languages (\p{Ll}) this would be the regex:

(?:[a-z\xB5\xDF-\xF6\xF8-\xFF\u0101\u0103\u0105\u0107\u0109\u010B\u010D\u010F\u0111\u0113\u0115\u0117\u0119\u011B\u011D\u011F\u0121\u0123\u0125\u0127\u0129\u012B\u012D\u012F\u0131\u0133\u0135\u0137\u0138\u013A\u013C\u013E\u0140\u0142\u0144\u0146\u0148\u0149\u014B\u014D\u014F\u0151\u0153\u0155\u0157\u0159\u015B\u015D\u015F\u0161\u0163\u0165\u0167\u0169\u016B\u016D\u016F\u0171\u0173\u0175\u0177\u017A\u017C\u017E-\u0180\u0183\u0185\u0188\u018C\u018D\u0192\u0195\u0199-\u019B\u019E\u01A1\u01A3\u01A5\u01A8\u01AA\u01AB\u01AD\u01B0\u01B4\u01B6\u01B9\u01BA\u01BD-\u01BF\u01C6\u01C9\u01CC\u01CE\u01D0\u01D2\u01D4\u01D6\u01D8\u01DA\u01DC\u01DD\u01DF\u01E1\u01E3\u01E5\u01E7\u01E9\u01EB\u01ED\u01EF\u01F0\u01F3\u01F5\u01F9\u01FB\u01FD\u01FF\u0201\u0203\u0205\u0207\u0209\u020B\u020D\u020F\u0211\u0213\u0215\u0217\u0219\u021B\u021D\u021F\u0221\u0223\u0225\u0227\u0229\u022B\u022D\u022F\u0231\u0233-\u0239\u023C\u023F\u0240\u0242\u0247\u0249\u024B\u024D\u024F-\u0293\u0295-\u02AF\u0371\u0373\u0377\u037B-\u037D\u0390\u03AC-\u03CE\u03D0\u03D1\u03D5-\u03D7\u03D9\u03DB\u03DD\u03DF\u03E1\u03E3\u03E5\u03E7\u03E9\u03EB\u03ED\u03EF-\u03F3\u03F5\u03F8\u03FB\u03FC\u0430-\u045F\u0461\u0463\u0465\u0467\u0469\u046B\u046D\u046F\u0471\u0473\u0475\u0477\u0479\u047B\u047D\u047F\u0481\u048B\u048D\u048F\u0491\u0493\u0495\u0497\u0499\u049B\u049D\u049F\u04A1\u04A3\u04A5\u04A7\u04A9\u04AB\u04AD\u04AF\u04B1\u04B3\u04B5\u04B7\u04B9\u04BB\u04BD\u04BF\u04C2\u04C4\u04C6\u04C8\u04CA\u04CC\u04CE\u04CF\u04D1\u04D3\u04D5\u04D7\u04D9\u04DB\u04DD\u04DF\u04E1\u04E3\u04E5\u04E7\u04E9\u04EB\u04ED\u04EF\u04F1\u04F3\u04F5\u04F7\u04F9\u04FB\u04FD\u04FF\u0501\u0503\u0505\u0507\u0509\u050B\u050D\u050F\u0511\u0513\u0515\u0517\u0519\u051B\u051D\u051F\u0521\u0523\u0525\u0527\u0529\u052B\u052D\u052F\u0560-\u0588\u10D0-\u10FA\u10FD-\u10FF\u13F8-\u13FD\u1C80-\u1C88\u1D00-\u1D2B\u1D6B-\u1D77\u1D79-\u1D9A\u1E01\u1E03\u1E05\u1E07\u1E09\u1E0B\u1E0D\u1E0F\u1E11\u1E13\u1E15\u1E17\u1E19\u1E1B\u1E1D\u1E1F\u1E21\u1E23\u1E25\u1E27\u1E29\u1E2B\u1E2D\u1E2F\u1E31\u1E33\u1E35\u1E37\u1E39\u1E3B\u1E3D\u1E3F\u1E41\u1E43\u1E45\u1E47\u1E49\u1E4B\u1E4D\u1E4F\u1E51\u1E53\u1E55\u1E57\u1E59\u1E5B\u1E5D\u1E5F\u1E61\u1E63\u1E65\u1E67\u1E69\u1E6B\u1E6D\u1E6F\u1E71\u1E73\u1E75\u1E77\u1E79\u1E7B\u1E7D\u1E7F\u1E81\u1E83\u1E85\u1E87\u1E89\u1E8B\u1E8D\u1E8F\u1E91\u1E93\u1E95-\u1E9D\u1E9F\u1EA1\u1EA3\u1EA5\u1EA7\u1EA9\u1EAB\u1EAD\u1EAF\u1EB1\u1EB3\u1EB5\u1EB7\u1EB9\u1EBB\u1EBD\u1EBF\u1EC1\u1EC3\u1EC5\u1EC7\u1EC9\u1ECB\u1ECD\u1ECF\u1ED1\u1ED3\u1ED5\u1ED7\u1ED9\u1EDB\u1EDD\u1EDF\u1EE1\u1EE3\u1EE5\u1EE7\u1EE9\u1EEB\u1EED\u1EEF\u1EF1\u1EF3\u1EF5\u1EF7\u1EF9\u1EFB\u1EFD\u1EFF-\u1F07\u1F10-\u1F15\u1F20-\u1F27\u1F30-\u1F37\u1F40-\u1F45\u1F50-\u1F57\u1F60-\u1F67\u1F70-\u1F7D\u1F80-\u1F87\u1F90-\u1F97\u1FA0-\u1FA7\u1FB0-\u1FB4\u1FB6\u1FB7\u1FBE\u1FC2-\u1FC4\u1FC6\u1FC7\u1FD0-\u1FD3\u1FD6\u1FD7\u1FE0-\u1FE7\u1FF2-\u1FF4\u1FF6\u1FF7\u210A\u210E\u210F\u2113\u212F\u2134\u2139\u213C\u213D\u2146-\u2149\u214E\u2184\u2C30-\u2C5E\u2C61\u2C65\u2C66\u2C68\u2C6A\u2C6C\u2C71\u2C73\u2C74\u2C76-\u2C7B\u2C81\u2C83\u2C85\u2C87\u2C89\u2C8B\u2C8D\u2C8F\u2C91\u2C93\u2C95\u2C97\u2C99\u2C9B\u2C9D\u2C9F\u2CA1\u2CA3\u2CA5\u2CA7\u2CA9\u2CAB\u2CAD\u2CAF\u2CB1\u2CB3\u2CB5\u2CB7\u2CB9\u2CBB\u2CBD\u2CBF\u2CC1\u2CC3\u2CC5\u2CC7\u2CC9\u2CCB\u2CCD\u2CCF\u2CD1\u2CD3\u2CD5\u2CD7\u2CD9\u2CDB\u2CDD\u2CDF\u2CE1\u2CE3\u2CE4\u2CEC\u2CEE\u2CF3\u2D00-\u2D25\u2D27\u2D2D\uA641\uA643\uA645\uA647\uA649\uA64B\uA64D\uA64F\uA651\uA653\uA655\uA657\uA659\uA65B\uA65D\uA65F\uA661\uA663\uA665\uA667\uA669\uA66B\uA66D\uA681\uA683\uA685\uA687\uA689\uA68B\uA68D\uA68F\uA691\uA693\uA695\uA697\uA699\uA69B\uA723\uA725\uA727\uA729\uA72B\uA72D\uA72F-\uA731\uA733\uA735\uA737\uA739\uA73B\uA73D\uA73F\uA741\uA743\uA745\uA747\uA749\uA74B\uA74D\uA74F\uA751\uA753\uA755\uA757\uA759\uA75B\uA75D\uA75F\uA761\uA763\uA765\uA767\uA769\uA76B\uA76D\uA76F\uA771-\uA778\uA77A\uA77C\uA77F\uA781\uA783\uA785\uA787\uA78C\uA78E\uA791\uA793-\uA795\uA797\uA799\uA79B\uA79D\uA79F\uA7A1\uA7A3\uA7A5\uA7A7\uA7A9\uA7AF\uA7B5\uA7B7\uA7B9\uA7FA\uAB30-\uAB5A\uAB60-\uAB65\uAB70-\uABBF\uFB00-\uFB06\uFB13-\uFB17\uFF41-\uFF5A]|\uD801[\uDC28-\uDC4F\uDCD8-\uDCFB]|\uD803[\uDCC0-\uDCF2]|\uD806[\uDCC0-\uDCDF]|\uD81B[\uDE60-\uDE7F]|\uD835[\uDC1A-\uDC33\uDC4E-\uDC54\uDC56-\uDC67\uDC82-\uDC9B\uDCB6-\uDCB9\uDCBB\uDCBD-\uDCC3\uDCC5-\uDCCF\uDCEA-\uDD03\uDD1E-\uDD37\uDD52-\uDD6B\uDD86-\uDD9F\uDDBA-\uDDD3\uDDEE-\uDE07\uDE22-\uDE3B\uDE56-\uDE6F\uDE8A-\uDEA5\uDEC2-\uDEDA\uDEDC-\uDEE1\uDEFC-\uDF14\uDF16-\uDF1B\uDF36-\uDF4E\uDF50-\uDF55\uDF70-\uDF88\uDF8A-\uDF8F\uDFAA-\uDFC2\uDFC4-\uDFC9\uDFCB]|\uD83A[\uDD22-\uDD43])

\b is not Unicode aware in JS so you can't use it for multi-byte letters - I'm not sure if you need it either. But if you do translate \p{L}\p{D} using above tools and use it in a negative lookahead (?!...) or simply do a (?!\S). The latter is more general but most of times satisfies the needs.