There is no problem at all with the first 3 sentences.
The 4th one isn't used.
The green light is on. Let's walk across.
The green light is on. Let's walk across the street.
The green light is on. Let's walk across on the crosswalk.
The green light is on. Let's walk across from the sidewalk.
Are the sentences above all grammatical? If not, would you correct them?
2 answers
Does this setence contain a dangling modifier?
When accelerating to make a green light, an accident can occur.
When accelerating to make a green light, an accident can occur.