Tamar,
You can accomplish this with RWG, and a skip. In short, assign the first four word-sentence stims to the same RWG group (e.g., 1). Then, assign two more word-sentence stims and the recall quiz to the next RWG group (e.g., 2). Here's the important detail: add a skip to the quiz, so after the quiz they move on to the next group of 4. That way, participants will have a quiz every 5-7 word/sentence pairs.
I've attached an example. I'm assuming you're using stimulus lists and compound stimulus presentations to achieve the word/sentence randomization.