GLI and GN
Gli is an l made with the middle of the tongue flat against the roof of the mouth, close to the lli in “million”. Gn is the same for n, like ny in “canyon”. Both are held a little long between vowels.
Saying gli as a plain l (figlio sounds like filo) or as g-l, and gn as g-n.
Hear the difference:
the thread / the son
the shovel / the straw
sleep / a dream