How can I answer the question "你什么时候开始学中文的?"
'什么时候' = 'what time' = 'when'
You can answer with one of the following:

[Since the time of ]. E.g. &quot;Started since 2016&quot; (從 2016 年開始)

[from a length of time ago]. E.g. &quot;Started from five years ago&quot; (五年前开始)



Q: &quot;你什么时候开始学中文的?&quot;


A: &quot;我是從2016年開始学中文的&quot;/ &quot;我是五年前开始学中文的&quot; (long version)


A: &quot;從2016年開始&quot;/ &quot;五年前开始&quot; (short version)


A: &quot;2016&quot;/ &quot;五年前&quot; (shortest version, just state a year or a length of time ago)

More example of '什么时候' question:
Q: 你什么时候吃晚飯的?
A: 晚上七時 (a time) If the question is about what is the regular time you have dinner'
A: 三小時前 (a length of time ago) If the question is about what specific time you ate your dinner tonight