The Grammar of Latin

I often recommend "none" when asked for a Latin program recommendation for the elementary years. I think the best use of the time spent on Latin in the K-6 years is to memorize all of the basic information that will need to be learned in a high school program. In keeping with the classical education model, this means that students are learning the grammar that they will need to become dialectic and rhetorical in Latin. This can be more effective (and so much less expensive) than workook pages.
I am influenced heavily by this Memoria Press article: Four Principles of Latin Instruction

There are several things to do in these K-6 years to prepare for teaching Latin in the later years:
Instill an appreciation of Latin
Learn Latin yourself
Teach Latin memory work

So let's take them one at a time

(1.) Instilling a love of Latin:

• Listen to a Catholic Latin Mass either in person or online
• Listen to Gregorian chant
• Look for Latin around you - University mottos, on money, in books, etc., etc.
• Study ancient Rome
• Learn to sing songs in Latin
• Listen to Latin texts being read aloud - at many places online including here
• Have fun with Roman numerals - for example, play Roman Sudoku

(2.) Learning Latin yourself:

First, some background resources: Bennett's Latin, Gildersleeve's Latin, Latin for Dummies (the last is fun to read if not a thorough, scholarly tome.) You can use these resources to learn about Latin yourself. Even Wikipedia is helpful (there must be many Latin geeks who love Wikipedia, because the articles there are pretty good.) You want to start with enough of an understanding that you can do the basic memory work. Then you will start learning what you will need to know to teach higher level Latin.

Probably the best plan is to use the Latin program you plan to teach in high school (Wheelock's, Henle, etc.) Work through it yourself over the years.

(3.) Latin memory work:

Much of the work can be done orally, so you can start with very young children. You can find some general ideas for what this can look like in How to Conduct a Recitation. Eventually, you will want to move to written memory work.

First, learn a bit about Latin pronunciation. This is an article on pronunciation from Wheelock's Latin.
What to memorize? Declensions, conjugations, vocabulary, and Scripture are a good start.

Declensions are a new concept for many. You can read a bit to explain them in this article from Memoria Press, which also explains conjugations. This Dummies page covers declensions as well, with the charts that you will want to memorize: Declining a Latin Noun. You can sing or chant the declensions. One resource for singing them is Latin Aids for Beginners.

Conjugations are more familiar, as most people probably learned English verb conjugations in school. These are generally chanted with an example word ("Amo, amas, amat, amamus, amatis, amant.") This is a nice chart of 1st and 2nd conjugations (there are four.) This chart would come in handy for all four. This is a chart of the endings alone for the present, future, and imperfect.

You will also want to learn some basic Latin vocabulary. Most programs use similar words. For directions on making Latin flashcards, see this article. You can also use online resources, such as the Latin sets on Flashcard Exchange and Quia. You can choose from many lists. This is a list of 200 Essential Latin Words. The advantage to making up your own memory work is that you can memorize them in a logical order (nouns together, prepositions together, etc.) rather than in the random way they are introduced in Latin programs. Here is list of verbs, another of prepositions, and the lists for words in Wheelock's Latin or Lingua Latina. You can find many, many lists by searching online. Memorizing common verbs, nouns, adverbs, and adjectives, a list of prepositions, and some pronouns will be a good start.

Whatever words you choose, make sure that you learn both forms, gender, and meaning for nouns and all four forms and meaning for verbs. They'll all be listed; just don't skip any of them, even though you may not know what to do with them yet.

You can also memorize Scripture passages in Latin. For example, Genesis 1:1-10 or John 3:1-6(scroll down to 'Reading the Bible in Latin.')

A fun way to learn this memory work is to play games. For example:

BINGO - You can start by playing BINGO with vocabulary words. Just put the first form of the noun or verb in the box, then call out the English form, or vice versa. BINGO is especially good for prepositions, too, which can be tedious and take a bit to memorize. Eventually, you can move to putting a specific form of noun or verb in each box. So the box would say, "puellarum" and you would say "of the girl" or "puella in the genitive plural" or even "girl in the possessive case." They would have to decline the noun in their head in order to get the correct form.

Hangman - You can do this several ways. I like multi-layered hangman, where the phrase discovered is actually a question in itself. The simplest form would be to play it straight with just a Latin word they are calling letters for. Then you can move to asking them questions, and if they get it correct, they get to try a letter. Then the phrase can be something like "second person plural form of narro." You could also have the phrase be an interesting tidbit about Roman history, or "the number twenty-three in Roman numerals," and they have to give you the Roman numerals.

Rolling a Die - A friend taught me this trick of hers. Cover a cube you construct from a cardboard box or pieces of cardboard with construction paper. Write different physical directions on it: "whisper," "shout," "on one foot," "holding your tongue," "in a baby voice," etc., etc. Each time you are going to do a chant or conjugate a verb or such, roll the die to get a funny direction.

Stopwatch - Stopwatches make everything more fun for dc. I don't know why they hold such power. Cut up a declension chart and time them putting it back together. It is made even more fun if you mock "throw" the pieces across the table for some reason. Time them to see how quickly they can recite a conjugation or declension. etc.

Memory - Put the Latin word for ten to twenty nouns on one card and the English on another. Turn them all upside down, lay them out on a table, and play Memory. They have to match the English and Latin pair to take it.

Military Drills - Run around the yard in mock army fashion doing call and response with Latin drills. Throw in a lot of gruff commands to the "soldiers" about keeping their knees up and such to add to the fun.

You can also use mnemonics, songs, and any other idea that works well with memory work in general.