The final cards in each pronunciation trainer are there to help you practice spelling rules, so that you can become more comfortable with them before you begin choosing and learning your own vocabulary. For these extra words, the “What’s the spelling?” card is definitely the most important model to use. If you would like to suspend the other two card models, here’s how:
Go to the browser, select that card model on the left side (similar to “2". Picture Words). You’ll see something like “mid:1366716141610” in the search field.
Next, add “card:3” to the search field, and it will give you a list of only the spelling cards. (You should see “Spelling?” in the “Card” column in the browser.) Select all those cards (you can shift-click to select a bunch of them in a row) and click “Suspend” up top. You can tell they’re suspended successfully when parentheses appear around the number in the “Due” field. For example, if it shows 197 cards under Due, they're not suspended. After you suspend them, it will show that number in parentheses, like (197).