Which word correctly fills in the blank: Oh, my French teacher - after the first few lessons, she _____ the whole class talking to each other in French?

The most suitable word to fill in the blank is "encouraged." In this context, the sentence suggests that the teacher actively motivated the students to engage in conversation in French. "Encouraged" implies that she inspired or gave confidence to the class to speak to each other, fostering an environment conducive to practicing the language.

This term emphasizes the role of the teacher as a facilitator who supports and inspires students to use what they've learned in a practical way. The action of encouraging aligns with the idea of promoting communication and interaction in a language learning context, which is vital for achieving fluency.

While "included," "involved," and "enabled" all convey a degree of participation or assistance, they do not carry the same connotation of motivation and support that "encouraged" provides in this scenario. Using "included" suggests mere participation without the aspect of motivation. "Involved" similarly denotes participation but lacks the element of inspiration. "Enabled" indicates that the students were given the means to speak but does not imply the encouragement needed to actually do so confidently.