Stop asking "What is the rule for 'used to'?" Ask: "What are the alternative choices in the system?"
The active/passive distinction is not merely a stylistic choice; it’s a systemic re-framing of who does what to whom. Stop asking "What is the rule for 'used to'
Syntax is the study of how words are combined to form sentences. English sentence structure typically follows a subject-verb-object (SVO) pattern, but there are many variations and exceptions. Language teachers need to understand how to construct and analyze sentences, including the use of clauses, phrases, and grammatical functions (e.g., subject, object, complement). including the use of clauses