Adj + to-infinitive

[kl004535]

Dear Teachers,

In my recent essay, I wrote

1. They are effective to complete their tasks.

However, my teacher changed it to the following sentence.

2. They are effective in completing their tasks.

I think mine is correct as well based on the analogy of the sentence below.

3. The boy is anxious to learn new things.

Is my sentence correct ?

Your help is highly appreciated.

Thanks

[Raymott]

Dear Teachers,

In my recent essay, I wrote

1. They are effective to complete their tasks.

However, my teacher changed it to the following sentence.

2. They are effective in completing their tasks.

I think mine is correct as well based on the analogy of the sentence below.

3. The boy is anxious to learn new things.

Is my sentence correct ?

Your help is highly appreciated.

Thanks

No, your sentence isn't correct.
Some adjectives can't be used that way.