Hypothetical complex sentence “如果……，就……”
In Chinese the pattern “如果……，就……” (rúguǒ..., jiù...) expresses a condition and its result.
The part after 如果 is the condition.
The part after 就 is the result that follows from that condition.
Basic Structure
如果 + Condition，(Subject) + 就 + Result
The Chinese frame:
如果……，就……
If …, then …
Key Rule
If the second clause has a subject, it comes before 就.
如果 + condition，subject + 就 + result
For example:
如果有时间，我就去上海玩几天
如果有时间 — if there is time
我 — the subject of the second clause
就 — then
去上海玩几天 — go to Shanghai for a few days
Examples
如果没走错，二十分钟以前就到了
Structure
如果没走错 + 二十分钟以前就到了
condition + result
如果 — if
没走错 — hadn't taken the wrong way
二十分钟以前 — twenty minutes ago
就到了 — would have arrived / had arrived
如果你需要帮忙，就给我打电话
Structure
如果你需要帮忙 + 就给我打电话
condition + result
如果 — if
你需要帮忙 — you need help
就 — then
给我打电话 — give me a call
如果有时间，我就去上海玩几天
Structure
如果有时间 + 我 + 就 + 去上海玩几天
condition + subject + 就 + result
如果有时间 — if there is time
我 — I
就 — then
去上海玩几天 — go to Shanghai for a few days
Quick Rule
如果 + condition，(subject) + 就 + result
Meaning: if …, then …
Example:
如果你需要帮忙，就给我打电话