To act decisively on the basis of information received or deduced.
"act on" is correct and usable in written English. You can use it to describe taking action on something, whether it's based on an instruction from somebody else or based on your own judgement. For example, "The president asked her to act on her plan as soon as possible.".
"You act on it".
"I act on autopilot".
Act on your own instincts.
* Source: Act on CO2/Carbon Trust.
"We must act on their behalf".
We should act on this knowledge.
People act on that".
When I feel like I can't trust my brain 100%, Ludwig really comes in handy. It makes me translate and proofread faster and my output more reliable.
Claudia Letizia
Head Translator and Proofreader @ organictranslations.eu