When reading a recent post by Karenne Sylvester called "Which came first: time or tenses?" (at http://kalinago.blogspot.com/2010/11/which-came-first-time-or-tenses.html) I thought it would be fun to see what sentences looked like without changing the form of the verb, but simply using modifiers or qualifiers to suggest the tense.
The table seen on the left (with some inspiration from http://www.athabascau.ca/courses/engl/155/support/verb_tenses.htm) is my attempt to answer that question.
What I'd like to know from readers is: when you look at these sentences, can you understand what is being said? In other words, ignoring the verb form, does the sentence communicate the intended time reference?
Having written them myself perhaps I'm too close to tell, but it seems to me that simply using the basic form of the verb (infinitive without the "to") does work. In each case the reader or listener, after getting over the initial shock, ought to be able to determine when the events were taking place relative to time.
When it comes to fluency and comprehension, it begs the question of whether we are sometimes too hard on our English learners who produce utterances like these, when we actually DO know what they mean.

Hi Jason,
The idea I got from this was that unplugged approaches work with beginners as well as with those having more language.
I also found it interesting as a potential approach with EFL beginners overseas, if only we could convince schools to give up their precious (badly written) student books & workbooks.
Where it is more difficult for you is not having a common L2 among your learners, making a co-teacher arrangement useless. Where it is simpler for you is being in an English-speaking country where students are exposed to the language outside of class.
It sounds to me that you are definitely on the right track with these students, offering them what they need and want. You've also got me thinking about how a similar approach might work here in Taiwan elementary schools. Are there more sample sheets that you have developed under the "English Trees" concept?
You don't mention many specific ways of eliciting language from students. I assume, though, you might have considered student art, gesture, facial expressions, acting out, bringing in photos or realia as other possibilities.
Please keep up the action research, as good ideas are always welcome.
Thanks,
Greg.
Posted today at http://jasonrenshaw.typepad.com/jason_renshaws_web_log/2010/11/a-simple-approach-to-trees-in-the-beginners-section-of-the-orchard.html