English is quite complicated to learn in detail, but a lot of it is very simple and unlike a lot of other languages, can be understood when some words are left out, or wrong tenses used. In some languages unless it's 100% right, you just get a blank stare and a look of total incomprehension.
Yes, we forget that a standardised English is a relatively recent occurrence. Same with French. Only once cars became more common and people started moving around their own country more did things really start to standardise. Radio helped a lot as well.