Conditional adverbial clause: "If there are very strict rules in place" This conditional adverbial clause sets up a hypothetical situation, that is, if there are strict rules in place, adding complexity and conditionality to the sentence.
Contrast structure: "But most places...are a little more flexible" Here, a contrast structure is used to show the difference in rules in different places, that is, some places are strict, while most places are more flexible, adding a sense of hierarchy and information to the sentence.
Modal verb: "can whisper, and even talk" Here, the modal verb "can" is used to indicate that under certain conditions children can whisper or even talk, demonstrating the accuracy and diversity of the answer.