English is three* languages in a trenchcoat, all languages borrow but English in particular is a cobbled together mess. Like a salors' pidgin language except instead of sailors, driven by the ruling class of Britain at the boundary of several language families who kept conquering each other.
*(or 7 or whatever number makes you feel best)
Might be a mess linguistically, but it's sure nice to have only 26 letters with no accents on a keyboard.
English is a West Germanic language with vocabulary from other languages, primarily French and Latin. But most of the core words are Germanic. It is not a pidgin whose defining feature is simplified grammar.