Ł or ł, described in English as L with stroke, is a letter of the Polish, Kashubian, Sorbian, Łacinka (Latin Belarusian), Łatynka (Latin Ukrainian), Vilamovian, Navajo, Dene Suline, Inupiaq, Zuni, Hupa, and Dogrib alphabets, several proposed alphabets for the Venetian language, and the ISO 11940 romanization of the Thai alphabet. In Slavic languages, it represents the continuation of Proto-Slavic non-palatal l (see dark L). In most non-European languages, it represents a voiceless alveolar lateral fricative or similar sound.
In Polish, Ł is used to distinguish historical dark (velarized) L from clear L.
In 1440 Jakub Parkoszowic proposed a letter resembling to represent clear L. For dark L he suggested l with a stroke running in the opposite direction as the modern version. The latter was introduced in 1514–1515 by Stanisław Zaborowski in his Orthographia seu modus recte scribendi et legendi Polonicum idioma quam utilissimus. L with stroke originally represented a velarized alveolar lateral approximant [ɫ], a pronunciation which is preserved in the eastern part of Poland and among the Polish minority in Lithuania, Belarus, and Ukraine. This pronunciation is similar to Russian unpalatalised <Л> in native words and grammar forms.
In modern Polish, Ł is normally pronounced /w/ (almost exactly as w in English as a consonant, as in were, will, wall but not as in new or straw). This pronunciation first appeared among Polish lower classes in the 16th century. It was considered an uncultured accent by the upper classes (who pronounced Ł almost exactly as: л in East Slavic languages or L in English pull) until the mid-20th century when this distinction gradually began to fade. Polish final Ł also often corresponds to Ukrainian word-final <В> (Cyrillic) and Belarusian <Ў> (Cyrillic). Thus, "he gave" is "dał" in Polish, "дав" in Ukrainian, "даў" in Belarusian (all pronounced [daw]), but "дал" [daɫ] in Russian. The old pronunciation [ɫ] of Ł is still fully understandable but is considered theatrical in most regions.
The shift from [ɫ] to [w] in Polish has affected all instances of dark L, even word-initially or intervocalically, e.g. ładny ("pretty, nice") is pronounced [ˈwadnɨ], słowo ("word") is [ˈswɔvɔ], and ciało ("body") is [ˈtɕawɔ].
In Polish Ł often alternates with clear L, such as the plural forms of adjectives and verbs in the past tense that are associated with masculine personal nouns, e.g. mały → mali ([ˈmawɨ] → [ˈmali]). Alternation is also common in declension of nouns, e.g. from nominative to locative, tło → na tle ([twɔ] → [naˈtlɛ]).
Some examples of words with 'ł':
In countries where Ł is not available, basic L is used instead. Thus, the surname Małecki would be spelled Malecki in a foreign country. Similarly, the stroke is sometimes omitted on the internet, as may happen with all diacritic-enhanced letters. Leaving out the diacritic does not impede communication for native speakers, but it may be confusing for those learning Polish.
Other languages 
The letter Ł is also used for non-Slavic languages.
In Venetian Ł is used in substitution for L in many words in which the pronunciation of L has become different for several varieties of the language, such as becoming mute or becoming the sound of English a and the Venetian e. For example: "la gondoła " can be pronounced as (in Venetian) "la góndola", or "la góndoa", or "la góndoea".
Ł is used in orthographic transcription of Ahtna, an Athabaskan language spoken in Alaska; it represents a breathy lateral fricative. It is also used in Tanacross, a related Athabaskan language.
Computer usage 
The Unicode codepoints for the letter are U+0142 for the lower case, and U+0141 for the capital. In the LaTeX typesetting system Ł and ł may be typeset with the commands \L and \l, respectively. The HTML-codes are Ł and ł for Ł and ł, respectively.
See also 
- Joseph Andrew Teslar & Jadwiga Teslar, A New Polish Grammar 8th Edition, Revised. Edinburgh: Oliver & Boyd, Ltd. (1962): 4 - 5. "ł = English l hard, dental ; ... It is true, of course, that the majority of Poles nowadays pronounce this sound with the lips, exactly like the English w. But this is a careless pronunciation leading eventually to the disappearance of a sound typically Polish (and Russian also ; it has already disappeared from the other Slavonic languages, Czech and Serbian) ... In articulating l, your tongue ... projects considerably beyond the horizontal line separating the gums from the teeth and touches the gums or the palate. To pronounce ł ... the tongue should be held flat and rigid in the bottom of the mouth with the tip just bent upwards sufficiently to touch the edge of the front upper teeth. (On no account should the tongue extend beyond the line separating the teeth from the gums.) Holding the tongue rigidly in this position, you should then pronounce one of the vowels a, o or u, consciously dropping the tongue on each occasion, and you will obtain the hard ł quite distinct from the soft l."
- Oscar E. Swan, First Year Polish 2nd Edition, Revised and Expanded. Columbus: Slavica Publishers (1983): xix. "ł (so-called barrel l) is not pronounced like an l except in Eastern dialects and, increasingly infrequently, in stage pronunciation. It is most often pronounced like English w in way, how. "łeb, dała, był, piłka."
- B. W. Mazur, Colloquial Polish. London: Routledge (1983): 5. "The sounds below exist in English but are pronounced or rendered differently: c ... h[, ] ch ... j ... ł as w in wet[, ] łach ład słowo[; ] r ... w"
- Б. Тарашкевіч. Беларуская граматыка для школ. – Вільня : Беларуская друкарня ім. Фр. Скарыны, 1929 ; Мн. : «Народная асвета», 1991 [факсімільн.]. – Выданьне пятае пераробленае і пашыранае
- Ян Станкевіч. Які мае быць парадак літараў беларускае абэцады  // Ян Станкевіч. Збор твораў у двух тамах. Т. 2. – Мн.: Энцыклапедыкс, 2002. ISBN 985-6599-46-6
- Campbell, George L. , Concise Compendium of the World's Languages. London: Routledge (1995): 354.
- "Ahtna Pronunciation Guide". Native Languages of the Americas. Retrieved 2008-10-05.
- Tuttle, Siri G. "Syllabic obstruents in Ahtna Athabaskan". Retrieved 2008-10-05.[dead link]
- Holton, Gary (April 2004). "Writing Tanacross Without Special Fonts". Alaska Native Language Center. Retrieved 2008-10-05.
- "Unicode Character 'LATIN SMALL LETTER L WITH STROKE' (U+0142)". FileFormat.info. Retrieved 2007-12-20.
Letter L with diacritics
Letters using stroke sign ( ◌̵ )