How best to learn French? By learning Interlingua first, of course

That's what someone said in response to a question on Yahoo! Answers just a few days ago; I just noticed it today. Here's the page.

The question was a fairly basic one, whether French is an easy language to learn or not. After a few general responses (if you know Spanish it'll be easier, millions of people learn French all the time so it must be easy, only feminine and masculine are a bit tricky, etc.) all of a sudden there's a plug for learning Interlingua first:

Probably the best way to learn French is by learning Interlingua first. Castellina found that people learned Interlingua so well in six days that they could write texts in it. The average may be closer to 15 days for speakers of English and other Germanic languages, but that's still very fast.

According to Gopsill, you can learn French, Italian, Spanish, Portuguese, any Romance language in about half the time if you've learned Interlingua. It works with other languages as well. So, I would especially suggest Interlingua for you, since you want to be multilingual some day.

I’m speaking from personal experience. I was practically fluent at Interlingua in about two weeks, and then I learned Spanish easily. In the long run, it saved me a lot of time and effort.

I know this to be true, though my experience is with Ido. When learning an international auxiliary language you only spend about a few days learning the grammar and other basics, and then it's just learning word after word and reading a lot of material, which probably takes about a month depending on the person. The person above says that he learned Interlingua in two weeks but note that this doesn't mean a complete knowledge of each and every word, because in two weeks there's no way to familiarize yourself with every single word that you would know in your own mother tongue for example, like pine, castaway, mace, erroneous, razor, overcast, etc. That's why after attaining a certain degree of fluency it's still good to spend a lot of time going over large dictionaries to see what you're missing, and then you can also begin to ease into French (or another language you want to learn) as you start to compare differences between Interlingua or another IAL and the language you want to learn.

Just to give an idea of how similar they are, here's part of the French-Interlingua dictionary recently published:

• obsessif obsessive
• obsession obsession
• cette idée devenait une ~ iste idea deveniva un obsession
• obsessionel obsessional
• névrose ~le neurose (-osis) obsessional
• obsidienne obsidiana
• monnaie ~e moneta obsidional
• art ~ arte obsidional
• obsolescence obsolescentia
• obsolescent obsolescente

Even better than this though, would be a complete French course in Interlingua. Or Latin. I've always thought that it would be a good idea for an IAL (especially one like Interlingua that markets itself as a modern Latin) to create an entire Latin textbook, to make the IAL a stepping stone to learning Latin. Especially because once one is published then perhaps a study could be commissioned to show that doing Interlingua for a year and then going to Latin is more effective than starting simply with Latin (if that's what the study shows), and if that turns out to be the case then it should receive a ton of attention.