I'm not sure which road I should take to the airport.

• I'm not sure which road to take to the airport.

Can you explain how I can apply for the visa?

• Can you explain how to apply for the visa?

She doesn't know when she should start her new job.

• She doesn't know when to start her new job.

We're trying to figure out what we should cook for dinner.

• We're trying to figure out what to cook for dinner.

Tell me why I should believe your story.

• Tell me why to believe your story.

She can't remember where she should meet her friends.

• She can't remember where to meet her friends.