When your kid starts understanding the differences between tenses, it is certainly a proud moment for you. You will feel a sense of excitement and joy when your kid will explain to you a past event with the use of perfect tenses.
What you need to know:
This is another step forward in his improved verbal language skills. If you use proper tenses while talking then he will pick it up from you and try and explain the event. Further he will use the same to explain different things to you. When he makes a mistake correct him and introduce him to the correct form of tense that needs to be used in a particular situation while appreciating him for his effort.