I cannot... with some tiny little exceptions.
I got 'conversation' fluent in French some years back, (not now, forgot nearly all of it). It got me thru France and Switzerland in my travels. I am NOT, nor ever was, "fluent" in French.
Italian... this one will be tough to explain and even tougher for you to understand. My grandfather spoke only Italian. Until I was about maybe 10 he was my closest friend and playmate. During that time I spoke to him all day, and he to me, no problem... it was not until later life that I it suddenly dawned on that I was speaking Italian. Have not since then, however, so it's lost to me.
Spanish. Been around spanish speaking people nearly my entire life. I can follow almost any conversation, at least the gist of a conversation, but can speak only a few meager words. Doesn't make much sense, does it?
And that's it.... never got fluent in any other language.... and it's one of my biggest regrets.
One other thing.... and I know this to be true, whether you believe it or not. Some people just have a knack for languages. We had a foreign exchange student who spoke, fluently, 7 languages. She learned Spanish while here.... in less than 2 months, and I'm talking 'fluently'. She learned German in a month. She could simply hear a word in a language she didn't speak ONCE and it was locked into memory.
My Dad and his siblings grew up speaking Italian, (didn't think to teach us kids).... and I was about to say that in their 'elder' years they didn't know when they were speaking Italian or English... but actually I think they were always like that, even when young.
And so... if you do, I'm jealous of you. Proud of you as well. - JamesJM