For giving a research presentation, I will need to refer to papers with multiple authors. When citing in the slides, I use the convention (as does everyone else) of 'et al.' How should I pronounce this when speaking during the presentation? I don't speak French fluently, but I know that the French pronunciation is 'ai-taal'. I am not sure how this would be pronounced in the English speaking world. What is the conventional pronunciation of 'et al.' in presentations for English speakers/researchers?
The standard English pronunciation can be found in a dictionary, see, e.g., et al. at MacMillan dictionary.
However, during a presentation, instead of reading that abbreviation, it is probably nicer to say something like: "Smith and his/her group/coauthors/colleagues published the paper [...]".
Another solution, if there aren't that many authors, is simply to say all names out loud when presenting. In my field, where papers with more than 5 or so authors are uncommon, sometimes we would use "et al." to avoid having to fit more than one or two names on the slide, but the simplest is to say all names out loud when presenting. (And afterwards you can just say "they".)
Of course, this requires sufficient familiarity with the work to know off the top of your head the name of all these authors.
The problem with "et al." is that, unlike "etc.," it changes depending on the gender of the other authors, which is not always easily apparent. There are actually three different forms (masculine, feminine, and gender neutral) meaning "and others" and an additional completely separate phrase also abbreviated "et al." that means "and elsewhere." One would argue you could just say the gender-neutral "et alia," but that is usually only supposed to refer to things without gender, not things with an unknown gender. Because of these complications and, as is often the case, an ignorance of the gender of the other people involved in the report, I would just pronounce it, "ett ahl."