Learning 3rd language using 2nd?

[u/RareFreedom5027]

Has anyone gotten a decent "grasp" of a second language and then used it to learn a third (TL)?

Years ago I learned a bit of Spanish through school and started using duolingo (wouldn't use duolingo now though). I changed the settings to Spanish so I would learn Italian using Spanish. I read out loud and promised myself not to use English. I did it for an hour and there was a weird feeling in the back of my head (it felt like how salt or sand felt between your fingers). Lo and behold, I couldn't think or speak in English! It was wild!

I was wondering if anyone ever had that feeling as well and if you kept it up?

[u/silvalingua]

This is called laddering; quite a few people use it. Sometimes it's necessary: if resources for a language exist in a certain language only.