Hindi's 'usko' already carries the 'to'
The indirect pronoun feels natural to Hindi speakers: 'usko likhta hoon' (I write to him) and 'usko phone karta hoon' (I phone him) both carry the same 'to' that Italian marks with 'a'. English hides it — 'I phone him', no 'to' — which is exactly why students slip into 'lo telefono'. Lean on the Hindi 'ko' and you'll reach for 'gli' / 'le' correctly. And the feared 'gli' sound is just Hindi 'ल्य' as in 'kalyaan' — a soft glide, 'lyee', not a hard 'glee'.
