The real kicker is phrasal verbs. You can have alright conversational English without needing most of these "advanced" grammatical features, which is a big part of why English has a reputation of being easier to learn in school than other European languages like German or Dutch.

It's when you're faced with a vocabulary list like "get up", "get on"/"get off", "get in"/"get out", "get through", "get on"/"get along", "get by", "get across", "get away with", "get back", and a myriad of other which in your native language each get a dedicated verb that you realize that English is not simpler, the complexity is just further up the road.

Also fun fact, if your native language is French, you can cheat and never use most of those, while accidentally using a much more formal/elevated register, because English has a habit of stealing French words when it wants to sound fancy.
"Get in" = enter (entrer), "Get through" = traverse (traverser), "Get by" = survive (survivre), "get across" ~ communicate (communiquer), "get back" = return (retourner).