Spoken Cantonese | using '緊', and difference between continuous and progressive aspects
In Cantonese grammar, 緊 indicates a ‘progressive’ aspect while 住 indicates a ‘durative’ aspect. Both aspects are part of the ‘continuous’ aspect of English grammar.

佢著緊件外套 (she is putting on an overcoat) describes a dynamic ongoing action of wearing the overcoat.
佢著住件外套 (she has on her body an overcoat) describes a static persistent state of already having the overcoat on her body.

佢拖緊兩個細路過馬路 (he is taking two kids across the road) denotes that “taking two kids” is the main action while crossing the road.
佢拖住兩個細路過馬路 (he is crossing the road with two kids tagging along) denotes that “taking two kids” is merely a subsidiary action of crossing the road.