Spoken by over 100 million native speakers worldwide, Punjabi is the 10th most widely spoken language (1). As the most common non-official-language mother tongues represented in the 2011 Canadian census report with 147,725 responses, Punjabi English speakers represent a huge portion of the Vancouver language landscape (2).
Here are some of the more common accented English challenges to focus on. They are certainly not extensive and don't go into depth about all the aspects or theoretical aspects but they should get you started.
As always, if there are any questions/comments along the way, let me know at email@example.com.
(1) Punjabi language. (2017, May 27). Retrieved May 28, 2017, from https://en.wikipedia.org/wiki/Punjabi_language
(2)Statistics Canada. 2012. Visual Census. 2011 Census. Ottawa. Released October 24, 2012.http://www12.statcan.gc.ca/census-recensement/2011/dp-pd/vc-rv/index.cfm?LANG=ENG&VIEW=D&TOPIC_ID=4&GEOCODE=933&CFORMAT=html#fd4_2 (accessed May 25, 2017).
(3) Faroqui-Shah, Y., Shah, A., Datta, H., & Kiran, S. (2010). Cultural Competence in Serving Asian-Indian Clients: Linguistic & Socio-cultural Aspects. ASHA Conference Presentation, retrieved from www.asha.org/Events/convention/handouts/2010/0500-Faroqui-Yasmeen.htm.
(4) Avery, P., & Ehrlich, S. L. (2012). Teaching American English pronunciation. Oxford: Oxford University Press.