I speak English and Bengali with similar proficiency, at least in the 'lower' registers of the languages. Since I was a small child in a bilingual home I've been struck by how, despite having different vocabularies, the two languages seemed very similar - faithful word-by-word translations could be performed on sentences without need to restructure or heavily rework their fundamentals or word order.. This contrasted later with my frequent frustration at the French and German learnt later at school, here even the concepts behind the language often seemed alien and upside-down.
I was wondering if any work has been done to compare the 'similarity' between languages and, if so, what languages most closely each other in this way. And which are most like English.