I LOVE languages!!
In most countries English is sufficient to get around, which is great :) (English is not my 1st language btw)
When I lived in Indonesia I learnt Bahasa Indonesia and in the end spoke it quite well.
When I lived with the Aboriginals in AustraliA for nearly half a year I started learning their language, of that tribe, Pitjantjatjara. At that time I was also expanding my English as I only had school English when I got to Aus, so basically learning 2 at the same time. Although I did of course had a very solid basis of English. It was more learning more and more words and phrases.
You can get the hang of a place without speaking their language. Getting to know a place and people and vibe hinges on your openness to learn and see and interact, not on speaking their language.
In actual fact, most people jump at the occasion to speak English, what little they know!
Dutch people are like that too. When I was living with my British partner we had Dutch youngster come around for our kids. And one in particular liked talking to me. He addressed me in... English!! While we are both Dutch
But he just loved the opportunity to practise and speak English.
The only place that I found was difficult was Marrakech, Morocco. Most do not speak English, not a single word, which shocked me to be honest. They speak Arabic and French. Unfortunately my French is more than rusty, hihi. So we had some tricky moments at times to figure things out. We wanted a compass, didn't succeed as we couldn't convey what we were looking for.
But these moments of using hands and feet to communicate have you open up and interact.
So no, you don't need to speak their lingo.
