they (I mean we) don't have "w" sound, so words like "want" "wine" "windows" "website" would be pronounced as "vant", "vine", "vindows", "vebsite"
Persian words don't start with two consonants, so when a Persian speaker tries to pronounce words such as "sport" or "start'; s/he would put a schwa before the first sound, these words would be pronounced like "esport" and "estart"
another tricky sound for us is the "th" , it's usually pronounced as "d" and sometimes as "t"
there are also some characteristics regarding the stress system of Persian language and how it is different with English stress system which needs a more detailed discussion
I recommend you to watch this short stand-up comedy show to see how an Iranian would sound when he tries to pronounce the word "gangster"!