にしたがって／したがい
Along with...
Structure
N/V る (indicating change) + にしたがって／したがい
Explanation
Shows B changing according to A objectively, as a regular pattern.
Examples
1北半球では北へ行くにしたがって気温が下がる。
In the Northern Hemisphere, the temperature drops as you go north.
2台風が近づくにしたがい、風雨はますます強まるでしょう。
As the typhoon approaches, the wind and rain will become increasingly strong.
3携帯電話が普及するにしたがって、通話料も安くなった。
As mobile phones became widespread, call charges also became cheaper.
4１８歳人口の減少にしたがい、留学生の入学に熱心な大学が増えた。
As the population of 18-year-olds declined, the number of universities eager to admit international students increased.
～に従って／従い
According to...
Structure
N + に従って／従い
Explanation
Indicates acting according to someone's instruction, advice, rule, or guidance.
Examples
1デパートが火事になったが、客は店員の指示に従って避難し、全員無事だった。
The department store caught fire, but the customers followed the staff's instructions, evacuated, and everyone was safe.
2親の勧めに従い、地元で就職することにした。
Following my parents' advice, I decided to find a job locally.
Note
1) Easily confused between two meanings of ～にしたがって／～に従って.
→ The form meaning parallel change is different from the form meaning “to follow instructions”.2) Look at the accompanying noun/verb.
→ If it's a natural change: use the change meaning.
→ If it's a rule or instruction: use the “according to” meaning.3) Do not mix the two meanings in the same sentence.
→ Each sentence should express only one usage.