[译] 老师给我们讲解了一道难题。
[误] The teacher explained us a difficult problem.

[正] The teacher explained a difficult problem to us.
[注] 动词 explain ( = make plain or clear) 意为“解释”用法与 give 不同，“向……解释”须在直接宾语之后加介词 to, 又如: The teacher explained division to the class. 老师给全班讲除法。/Please explain this rule to us. 请把这条规则讲给我们听。