There appears to be a lot of confusion regarding Gurmukhi and Punjabi.
The assumption a lot of people seem to make is that there is a language called Punjabi (what we use everyday) and there is the language called Gurmukhi - the language used to write the Guru Granth Sahib.
So is there two languages ??
Did the Guru's use different language called Gurmukhi??
The answer is No.
Before going further ,apply some logic yourself, would you (if trying to convey a message to a lot people) write the message in new language , which everybody would have to learn before deciphering the message , OR would you write in the most commonly used language ??
Remember this - Punjabi is language ( what we speak). Gurmukhi is a script (how we write punjabi ).
Punjabi is an Indian language which belongs to the outer-circle of the Indo-Aryan languages and distantly related English being a member of the same Indo-European language family. It is a modern Indo-Aryan language spoken mainly in the Punjab states of both India and Pakistan. It nearly resembles Hindi and Urdu.
There are 2 main scripts used , Punjabi speaking Muslims may write Punjabi in the Perso-Arabic script (as used to write Urdu, writing from right to left), this sometimes is referred to as Shahmukhi. ( I will try to get examples of this, if you have any please send to me ).
Punjabi is also written using Urdu and Hindi scripts.
Punjabi speaking Sikhs write Punjabi in the Gurmukhi script , which was developed by Guru Andgad dev ji.
Contrary to another popular belief , Guru ji did not invent Gurmukhi from scratch , he modified the Landa (lahnda) script . He and polished the landa script to reflect , pronunciation and the authentic tonal expressions to what is known as Gurmukhi today. The Landa had been around for centuries before the Guru Ji's.
However we must also remember that punjabi itself has evolved along with time, as any language does. There will be differences between 16th and 17th century and now.
Also did you also know that there are different dialects of Punjabi ?
Here is a brief outline of them.
Majhi
Spoken in the heart of Punjab i.e., Lahore , Sialkot, Gujaranwala, Gurdaspur, Amritsar. Most of the population of Punjab lives in this area and linguists also say that Majhi dialect is the "Tixali boli" i.e., it has been influenced by all other dialects
Malwi
Spoken in the east Punjab area of Ludhiana, Ambala, Bathinda, Ganganagar, Maleerkotla Fazilka, Ferozepur. This area (Malwa) is the southern and central part of present day Indian Punjab. Also includes the Punjabi speaking areas of Haryana, viz. Ambala, Hissar, Sirsa, kurukhetra etc. (northern parts of Haryana mainly).
Doabi
Land between the rivers of Beas and Satluj is called Doaba. Do Aaba lierally means "the land between two waters" in persian. It includes Jalandhar, Hoshiarpur.
Pothohari
The area where Pothohari is spoken extends in the north from Kashmir to as far south as Jehlum and Gujar Khan and includes the capital of Pakistan, Islamabad. This dialect is similar to some extent to the Hindko dialect of Punjabi which is spoken in Peshawar, Nowshehra, Mansehra all these areas lie in the North West Frontier Province of Pakistan where majority language is Pashto, but Hindko speakers area also found in sizable numbers.
Jhangvi
The region where Jhangvi is spoken stretches from Khanewal to Jhang and includes the cities of Faisalabad, Chiniot. Jhangvi dialect is also called the ``Jangli'' dialect of Punjabi.
Multani
The dialect spoken in Multan, Bahawalpur, Khairpur, Daira Ghazi Khan, Muzafar Garh i.e., southern deserts of Punjab is called Multani (also Lehndi by some) and perhaps differs from Punjabi more than any other dialect. Those who closely know the dialect say that it is a very "mithi boli." This is the land of Muslim Sufis, perhaps "Shah Shams Sabazwari" who came to Multan in 1165 AD was the first in a long series of Sufis to base themselves in Multan. Multani becomes more and more different as you move down south, as the influence of Sindhi increases, it is also known as Siraiki there. Siraiki itself is Sindhi word and means northern.
More Information regarding Punjabi by Serjinder Singh
The cliche that Guru Angad Dev ji made the Gurmukhi alphabet is patently false(It was propagated by the enemies of Sikhism known as Handalis who wrote the distorted biography of Guru Nanak Dev ji called Janam Sakhi Bhai Bala).
If one reads that part of Guru Granth Sahib which is known Patti one finds that this Gurbani written by the first Guru ji mentions the letters of Gurmukhi by the same names as we know them today. If Guru Angad Dev ji made the Gurmukhi alphabet how Guru Nanak Dev ji could have mentioned it in his bani several decades earlier. This script known as Gurmukhi or literally the script used by Gurmukhs existed long before.
Word Gurmukh did not necessarily refer to Gursikhs alone at that period of time but was used by Naths and Sidhs as well. Guru ji in his discussions with the Sidhs use this word to address them as given in the Guru Granth Sahib under the bani titled "Sidh Ghost". All the relevant arguments in support of the above are given in the text books of degree students in Punjab who study the history of Punjabi language and script. In Ludhiana district of Punjab there is a village named Hathoor. There is a sacred well where pilgrims who were traders used to visit and used to get some bricks with their names and details of donations given laid on the inside wall. One of these is written in Gurmukhi as we know it today and gives the date which is in thirteenth century which is long before Guru Nanak Dev ji. I am refering here to the script which is Gurmukhi.
As far as the language is concerned in Punjab the language that is and was spoken is called Punjabi. Now this Punjabi was similar to the Punjabi that we speak in our homes even now. One can read the Saloks of Baba Farid in Guru Granth Sahib which even you born in the west would be able to understand because these are in Punjabi. Baba Farid lived during the thirteenth century couple of centuries before Guru Nanak Dev ji. In their blind chauvinistic aim to show that the Gurmukhi script belongs only to Sikhs and not to rest of the Punjabis these bigots have created hatred against non-sikhs and alienated them from their own language and past and divided the population of Punjab on religious lines.
The Majhi was called Taxali Boli in earlier part of this century not because it is influenced by other dialects. On the contrary it was considered by some egoist intellectuals living around Lahore and Amritsar that the dialect they speak should be considered standard Punjabi or authentic Punjabi and other dialects were ridiculed.
Word Taxal means mint where authentic coins are made. So, Taxali Boli like the authentic minted coins means authentic or standard language. At present nobody subscribes to this view. Respect shown for all dialects of Punjabi is same. In addition to the dialects listed by you there are some more viz. Puadhi which is spoken in the area between Chandigarh, Patiala and Ropar near the foothills. Dogri or Pahari spoken in Jammu and Mirpur area is also cosidered a dialect of Punjabi.
Okay so far ?
The next argument usually seems to be , why is Guru Granth Sahib so difficult to comprehend , so it cannot be same language ?
Well the language used in it is not uniform , it contains Hindi, Braj Bhasha, Sanskrit, Marathi, Pharsee, Arabic and also the many dialects of punjabi. Sometimes the words are pronounced the same as an existing punjabi word yet the meaning maybe different due to the origin of the word.
Furthermore as mentioned above any language is always in a state of flux, constantly evolving.
More Information regarding Punjabi by Serjinder Singh
Regarding the Gurmukhi script, it is derived from Brahmi used for Asoka's edicts. The Landa script is by and large Gurmukhi script without the vowel signs. In Panjabi word Landa means an animal that has lost its tail. Thus the script which does not have its Siharees or Biharees or Hora, Kanna etc is similar to an animal without a tail. That is why it is called Landa. The Landa script has been in use and still is used for writing accounts in Bahee's by the traders in Punjab. Otherwise the Gurmukhi script was known long before Guruji along with the vowel signs.
An Arab mathematician mentions in tenth century of a mathematician from Punjanb whom he saw using a single letter for each numeral whereas till then the Romans and the Arabs had been using several letters for one numeral. For instance, for three one wrote III and for eight VIII. In Punjab at that time three was written as 3 which is nothing but the first Gurmukhi letter of the Punjabi word tin for three and 2 is the modified first letter of Punjabi word Do(pronounced as though) for two. No one has noticed this but I can show conclusively that all the nine numerals (which are known as Arabic numerals in West, but Arabs call them Hindsa, meaning brought from Hind or India)are the different letters derived from the Punjabi count words.sucha Ik, Do, Tin, Chaar, Punj etc. Indeed the Arab mathematicial mentions the origin as Punjab of the Hindsas or numerals.
So remember Punjabi is a LANGUAGE , Gurmukhi is SCRIPT
If you have any views regarding this add them to discussion forum.
Many thanks to Serjinder Singh
and also Muhammad Afzal Upal for his information about punjabi dialects.