In working on our Spanish course, I spent most of last week decoding Spanish dialogs into English. (If you are unsure of what "decoding" really means, make sure you get a copy of our free e-book on our website www.SpeakEZLanguages.com - it explains it in detail.)
I should probably preface this by sharing the extent of my Spanish knowledge: I never attended a class, but spent 27 hours (yes, I counted, I wanted to know!) listening actively to the Birkenbihl Spanish course that exists for German native speakers. I did many many more hourse of passive listening, but that doesn't really count as time since I was concentrating on something else while I was playing the tapes.
Then I had a Spanish-speaking friend who wanted to keep up her Spanish and we decided to talk every morning on the phone for 30 minutes. We did that for about 6 weeks before other things started to take precedence. That was in 1999. I haven't spoken Spanish since, I just never had the need for it.
I did however pick up a book in Spanish about 5 years ago because the publisher had run out of English translations and I was determined to read it. Being eager to learn about something is very motivating!
In terms of listening to Spanish, I did get 7 years of daily exposure on the NYC subway... however, I couldn't understand most of the accents because the tapes that I had learned with were recorded by native Spaniards and sounded quite different from the Puerto Rican accent!
Back to the decoding exercise: I was happy to see that I was able to guess most of the words, primarily because I was familiar with the topics. I checked the remaining words at www.wordreference.com, which I found very helpful.
Conjugated verbs were the greatest challenge, and I was glad to find out that I could type any verb form - even without accents - into the wordreference search box, find out what the infinitive was and which person and tense I was actually dealing with - priceless!
I was thinking about how someone who has no knowledge of grammar and/or grammatical terms would go about doing this. The best I can think of is to start with a regular textbook. They all have vocabulary lists for individual chapters, as well as the grammar covered in each chapter. Since the grammar is being introduced little by little, you could figure out relatively easily how to translate verb forms into English without worrying about being faced with a subjunctive in your first lesson.
What's bothering me about that is that it will take you forever to understand the "regular" language as people speak it in everyday life. In the end, it will be more efficient to either have someone bilingual help you with decoding, or to get a text that is already decoded.