Grammar exercises: The sentence particles 吧 (ba) and 吗 (ma) in Chinese grammar 语法:吧、吗 练习
The example sentences of the article, a few to an exercise, in the order the article shows them. Each exercise takes the point's word out of a sentence for you to fill back in, then gives you the sentence's words to put in order, and an item you miss comes back later in the same sitting.
2 grammar exercises over 24 items.