"When you learn one Romance language, to a considerable extent you learn them all". Discuss.

[Tooting Carmen]

English is kind of an outlier though, I believe other Germanic languages could be closer to one another, even comparing West Germanic no North Germanic ones. Not only vocab but in parts grammar, pronunciation and syntax too.

I'd still say that Portuguese, Spanish and Italian at least are closer together than Dutch and German would be with Danish, Swedish and Norwegian.

[Etelfrido]

I'd still say that Portuguese, Spanish and Italian at least are closer together than Dutch and German would be with Danish, Swedish and Norwegian.

I definitely agree, but when one adds French and Romanian the picture gets blurrier in my opinion.

[Tooting Carmen]

I definitely agree, but when one adds French and Romanian the picture gets blurrier in my opinion.

Granted, but still both of those are closer to the PT-ES-IT axis than English is to Dutch and German (never mind the Scandinavian languages).

[Etelfrido]

East Asian languages as a whole are considerably different from one another: some Chinese dialects aren't mutually intelligible, Austronesian languages can vary widely, until the present time Japanese has only been proved to be related to the small Japonic family and Korean to the Koreanic one.

Atlantic-Congo languages occupy most of SSA and the largest branch is Bantu, from what I've read some are mutually intelligible but not all, so they could be a contender to Romance and Slavic languages.

Out of Uralic languages I know Hungarian is very removed from Finnish and Estonian.

Native American languages are extremely diverse.

Arabic and Hebrew seem not to be intelligible either as they've separated from a common ancestor a long time ago but I've been told they're closer than one might've expected because for being religious languages their standard forms have been pretty conservative.

Some say Turkic language speakers can understand other Turkic languages.

I'm not sure about Indian languages.

[Dandelion]

Hungarian is said to be fairly close to Khanty, very far to the East,

[Hulu]

I learned French first. I think that helped me more with English than Italian. English has more in common with both than the two with each other. But Italian is very helpful with Spanish.

[Tooting Carmen]

English has more in common with both than the two with each other.

LOL what? French and Italian are the most lexically similar languages to one another. 'bonjour'/'buon giorno', 'bonsoir'/'buona sera', 'fromage','formaggi', 'manger'/'manggiare', 'trop'/'troppo', 'encore'/'ancora', 'alors'/'alora'...

But Italian is very helpful with Spanish.

True.

[noricum]

My thesis: When you speak English, you are already halfway through speaking a Romance language.

I feel that on vacation in Italy, Romance words I know from English proved more helpful than the A1-level Portuguese course I took ages ago.

[gixajo]

Write that sentence in Dutch and see how it compares. On the other hand:

"Je pense toujours que ma connaissance d'hollandais vraiment aidait mon anglais, malgre tout ca. C'est un sujet a converser interessant de tout facon".
"Yo pienso todavia que mi conocimiento del holandes verdaderamente ayudaba mi ingles, a pesar de todo eso. Es un asunto para conversar interesante de cualquier forma".
"Eu penso ainda do que o meu conhecimento do holandes verdadeiramente ajudava o meu ingles, a pessar de tudo isso. E um assunto para conversar interessante de qualquer maneira".

I don´t know Portuguese but in French and in Spanish we can do it more similar than you did.

"Malgré tout ça je pense toujours que ma connaissance du neerlandais a vraiment aidé mon anglais. De tout façon, c´est un sujet interéssant a discuter"
"Pese a todo eso yo pienso todavía que mi conocimiento de neerlandés ha verdaderamente ayudado a mi inglés. De todas formas, es un tema interesante a discutir"

Surely a Portuguese member can find also a way to made the Portuguese text even more similar to them, changing the order of words or choosing closer vocabulary in their language.

[Boudin]

English	The sun shines in the blue sky.
German	Die Sonne scheint am blauen Himmel.
Dutch	De zon schijnt aan de blauwe lucht.
Swedish	Solen skiner på den blå himlen.
Norwegian	Solen skinner på den blå himmelen.
Danish	Solen skinner på den blå himmel.
Icelandic	Sólin skínur á bláum himni.

French	Le soleil brille dans le ciel bleu.
Italian	Il sole brilla nel cielo azzurro.
Spanish	El sol brilla en el cielo azul.
Portuguese	O sol brilha no céu azul.

It's easy to find examples for English with any of the Romance languages too, but the grammatical articles won't match.