A good source to learn the Pali language?

The techniques for learning Pali are much the same for learning any language.

Something unusual about Pali as a language of Buddhism is that the language is a little different from country to country, especially with respect to pronunciation.

Flash cards, although sometimes boring, are the most effective way to learn enough words in a language to become proficient in it.

ref: http://newbuddhist.com/discussion/7151/pali-flashcards

Because people don't like flash cards, there are a million and one other techniques for learning a language, this is a website with lots of people with good advice.

It would be better to enroll yourself and learn Pali from any university or institute but if you feel that you can manage to do it on your own then you'll have to depend on reading and understanding books etc.. Apart from that you'll need to be in contact with a Pali teacher who may guide you step by step, which will be fruitful.

There's An Introduction to Pali over ZOOM • A Summer Intensive Course

No prior knowledge of Pali is required. The course will start with the basics, showing students how the alphabet is organized and how to find words in a dictionary. Basic grammar will be covered in depth. Students will begin to read passages of the Pali canon themselves.

This course will use two textbooks. The first, Lily De Silva’s Pali Primer, is available in print as well as freely available on line. This text starts with very simple sentences that introduce the noun and verb forms of Pali. Once this book is worked through, A New Course in Reading Pali: Entering the Word of the Buddha by James Gair and W.S. Karunatillake will be used to begin reading the Pali canon. Additional materials will be made available for students via dropbox.

The first lesson was two days ago, the next starts in a few hours from now.

This answer will be rapidly out of date -- the course is 5 weeks, 2 days a week, 75 minutes per day, via Zoom and with a live (not being recorded) overflow on YouTube.

• Courses

  • Partiyatti Learning Center offers two free online Pāli courses.

  • Pali Online School at the Oxford Centre for Buddhist Studies is a very intensive 3-week online Pāli course, that involves live instruction by prof. Richard Gombrich, a well-known scholar of Theravāda. The aim is to enable students to read original canonical texts in Pāli, with the aid of dictionares and grammars. The course is expensive, but I've taken it and can wholeheartedly recommend it. I doubt there is any other way to learn a good deal of Pāli in such a short time.

• Dictionaries

  • Pali-English Dictionary (PED) by Rhys Davids and Stede is the most comprehensive fully published Pāli dictionary available to date. It is freely available online, but the search interface has some strange bugs (the anusvara needs to be typed as ŋ instead of the standard ṃ, and the first letter of a headword must be written in uppercase if it contains a diacritic, e.g. Āsana instead of āsana). http://dsal.uchicago.edu/dictionaries/pali/

  • Several Pāli dictionaries, including the PED (though not all the entries), are available here. The search interface is much more user-friendly, but lacks more advanced features of the aforementioned one (it's not possible to search for words in definitions, words that start/end/contain a particular character sequence, etc.). https://palidictionary.appspot.com/

  • A PDF version of the PED is freely available, as well as a text version in a single big file.

  • Dictionary of Pali by Margaret Cone is an improvement over the PED, with more usage examples, but only volumes I (A-Kh) and II (G-N) have been published (note the different alphabetical order in Pāli).

• Books

  • A Pali Grammar by Wilhelm Geiger, revised by K.R. Norman
    • Describes phonology (the sound system) and morphology (how words are inflected), but has no information about syntax (how words are combined together)

  • An Introduction to Pali by A.K. Warder

    • generally regarded as the standard Pāli textbook
    • teaches about compounds (samāsa) and about some aspects of syntax and idiomatic language use, that is, the topics that are absent in Geiger's grammar
    • however, according to prof. Gombrich, the book cannot be relied on, because it contains strange mistakes, and sometimes is unclear or misleading

  • If you follow a tradition that involves chanting in Pāli (by the teacher and/or by the students), it may be useful to take a look at the chanted texts and their translation. In such case you are already familiar with the pronunciation and rhythm of the text, so learning should be much easier. For example, this book may be useful for people who follow S.N. Goenka's tradition:

    • Gem Set in Gold, Dhamma Chanting: English Translation with Pali and Hindi by S.N. Goenka

• General

  • Access to Insight provides a list of resources for learning Pāli.

  • The Pāli Canon and its translations are obviously important learning resources, available on SuttaCentral and Access to Insight. See also answers to this question.

  • Here is a nice set of well-known Pāli chants on YouTube, with their transcription and translation into English. It's a good starting point for learning Pāli pronunciation.

  • For learning vocabulary, I recommend making flashcards in a spaced repetition program (the most popular one is Anki). Spaced repetition is a general way to memorise things in the long term, and it is tremendously useful for language learning. It is especially useful if you don't read Pāli texts regularly and don't want to forget the words.