The phrase "able to know when" is correct and usable in written English.
It can be used when discussing someone's capacity to recognize or understand specific moments or situations.
Example: "She is able to know when the right time to speak up is during meetings."
Alternatives: "capable of recognizing when" or "able to discern when".
And I want to be able to know when I can pick up Henry from school".
This means that Google won't just be able to know when you cook, but also see what you cook.
It's just having the right timing, and being able to know when to go up and get it".
We are now able to know when students are not on track to graduate even in elementary grades and to intervene.
If follow-up studies validate the findings, women in their twenties may be able to know when they will stop ovulating.
I am not sure how best to answer, but it appears that the difficulty people are having might be associated with being able to know when one can say that shaft work occurs.
Stealing bases against low-level minor leaguers is far different from doing it against major leaguers, in terms of being able to read pitchers and to know when to go and when to wait.
Do not attempt this though until you have enough control over your board to be able to hold the edge and to know when you have enough speed to make the turn.
Many children want to know when they will be able to hit it.
"Women, no matter what their circumstances, must get to Westminster on their own merits and be able to know that when they're sitting in the House of Commons," she said.
Comcast CEO Owns Up To It Being The "Worst Company In America" – In response to winning the horrible distinction, Comcast CEO Neil Smit said improving customer service is his top priority, and he wants customers to be able to know exactly when a technician will arrive.
