Como dizer "Falar pelos cotovelos" em inglês

Dicas:

A expressão 'falar pelos cotovelos' não é comum, pelo menos aqui onde moro, no contexto apresentado. Aí vão algumas sugestões:

Falar pelos cotovelos(falar muito): To be talkative, talk a lot

She is talkative. (Ela fala pelos cotovelos.)-->Fala muito

Falar pelos cotovelos(falar demais): Talk nineteen to dozen, talk too much

She talks too much.(Ela fala pelos cotovelos.)

Sua sugestão:

-->"Just think how nice it would be to be able to speak English as much as you want to."

Bons estudos.

Falar pelos cotovelos = talk one's head off

Talk someone's head/ear off[/b], to bore or weary someone by excessive talk; talk incessantly:

All I wanted was a chance to read my book, but my seatmate talked my ear off.

Talk one's head off

Fig. Inf. To talk endlessly; to argue vigorously.
I talked my head off trying to convince them. Don't waste time talking your head off to them.

Ref. dictionary.reverso
Ref. dictionary.reference

Carminha, even dough I posted this expression above I still thinking that for you sentence is better say as Donay did or just say something like:

Já pensou que legal ??! Daqui a pouco sair falando pelos cotovelos..." (no caso, falando inglês pelos cotovelos)
Obrigada a todos

I cant wait to speak English fluently!

Actually it will be nice to speak in English the same way I do with Portuguese
etc

To ones mouth,

Ricky is running his mouth he wont do anything to you.

To have a big mouth could fit also

No, I don´t talk a mile a minute!

Talk a mile a minute, means both (sometimes at the same time): talk excessively OR quickly.

To have a big mouth usually is about someone that talks carelessly (and sometimes spill the beans...), but indirectly they also talk more than should do.

To talk a blue streak

Exemplo: (...) at Yale Rep the actors talk a blue streak, especially in the bakery scenes where the jokes might have drawn laughter if they didn’t go by so quickly. Ref. playsinternational.org

And in Portuguese also "falar como o homem da cobra", "(alguém parecer) ter tomado água de chocalho", etc.

A blue streak - means (algo) "rapido e incessante"

There is also "swear/curse a blue streak" (falar uma "carrada", dizer um monte de palavrões e insultos, etc ). Implícito que a pessoa 'esgotou' todo o repertório de palavrões e insultos no momento, descarregando frustração, por exemplo (at the moment of snapping, losing of control, and so on).

To drone on

Exemplo: STOP me if I’m droning on, but I have good news. Ref. thesun.co

I would like to add an aside note, if I may; "droning on" would typically be about a a dull, monotonous, and often lengthy, tedious/boring way. In such a way that listener could lose interest or fall asleep!

Drone has been a trend in language as well, today we speak of "drone parents" the ones that are controlling and tracking their children's lives (using technology, cameras, apps, all that jazz).
Could also be the hovering, hyper-involved parent, the one that isn't language "wealthy" enough to be a helicopter parent! LOL.

To the non native speaker of Portuguese, I'll explain "o homem da cobra" was that street vendor guy. The guy that had 'a street artist' style, the one that was talkaholic and with a 'hypnotic conversation' and pattern, a highly connecting and convincing kind of guy.
He would bring a snake with him, and it would be the 'highlight' (o ponto alto) of his presentation, but then he would have already sold everything in the world to the passersby! Even snow to an eskimo!

The expression evolved to describe people that talk non-stop and (sometimes) exaggerates, overdo in the histrionics.
Curiously, in rare occasions people say that a female person "fala mais que a mulher da cobra", but it's commomplace to say "ela fala mais do que o homem da cobra", referring to females as well.
Another way to express that is "ela/ele" parece que tomou água de chocalho.", mostly in the Northeast region of Brazil.

People also would say that when they are bored by somebody's long-winded speech!

By the way, in anatomy they call it "cubito" (cubitus, "cotovelo" in Latin), but in language it's a fixed expression, so "falar pelo cubitos" didn't catch on.