If you are responsible for doing something, it is your job or duty to do it.
Be Careful!
Don't say that someone is 'responsible to do' something.
If you are responsible for something bad that has happened, it is your fault.
Be Careful!
Don't use any preposition except for after responsible in a sentence like this.
Responsible can also be used after a noun. If you talk about 'the person responsible', you mean 'the person who is responsible for what has happened'.
However, if you use responsible in front of a noun, it has a completely different meaning. A responsible person is someone who can be trusted to behave properly and sensibly.
Responsible behaviour is sensible and correct.
Adj. | 1. | responsible - worthy of or requiring responsibility or trust; or held accountable; "a responsible adult"; "responsible journalism"; "a responsible position"; "the captain is responsible for the ship's safety"; "the cabinet is responsible to the parliament" obligated - caused by law or conscience to follow a certain course; "felt obligated to repay the kindness"; "was obligated to pay off the student loan" prudent - careful and sensible; marked by sound judgment; "a prudent manager"; "prudent rulers"; "prudent hesitation"; "more prudent to hide than to fight" trustworthy, trusty - worthy of trust or belief; "a trustworthy report"; "an experienced and trustworthy traveling companion" irresponsible - showing lack of care for consequences; "behaved like an irresponsible idiot"; "hasty and irresponsible action" |
2. | responsible - being the agent or cause; "determined who was the responsible party"; "termites were responsible for the damage" causative - producing an effect; "poverty as a causative factor in crime" | |
3. | responsible - having an acceptable credit rating; "a responsible borrower" trustworthy, trusty - worthy of trust or belief; "a trustworthy report"; "an experienced and trustworthy traveling companion" |