Do not take too many chances when you drive at night.

I know too is an adverb modifying many an adjective
I know when is an adverb. Does it modify drive?

"when" is the introductory word for the dependent clause "when you drive at night."

That dependent clause as a whole modifies the verb, "do take"

Yes, "too" is an adverb modifying "many."

"When" introduces the adverb clause, "when you drive at night." The clause modifies "do drive."

Also -- "not" is an adverb modifying the verb "do take."

Actually, in this context, "when" is not functioning as an adverb but as a conjunction. It joins two clauses: "you drive" and "at night" to form a complex sentence.

In this sentence, the main clause is "Do not take too many chances," which is giving a command or instruction. The subordinate clause "when you drive at night" provides additional information about when the command should be followed.

To better understand the role of "when" in this sentence, let's break it down:

- "You drive" is the main clause, expressing the action being performed.
- "At night" is a prepositional phrase serving as an adverbial phrase, providing more information about the time or circumstance of the action.

So, instead of "when" modifying "drive," it acts as a conjunction introducing the subordinate clause that modifies the whole action of driving.