tense - "The front door slid open" grammar explanation

The front door slid open.

I am curious about "slid open" in this context. Is "slid" a verb or an adverb? Is "open" a verb or not?

Is a "slide open" a phrasal verb like "push open"?

Answer

I wouldn't call it a phrasal verb. In phrasal verbs, the the two words together take on an entirely new meaning. For example, when I say:

Why don't you grow up?

I don't mean, "Why don't you grow taller?"; I mean, "Why don't you act more mature?"

However, when I say:

Would you please slide the door open.

I mean exactly what the two words mean: open the door, by sliding it.

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The next part of your question is interesting. My first thought was that slide is the verb and open is an adverb:

• 
  

  Please slide the door open.

  
  


• 
  

  Please slide the door closed.

  
  


• 
  
  

  Please slide the door to let some fresh air in.

  
  

But that last one seems a bit peculiar. It seems like I am trying to say:

• Please open the door to let some fresh air in.

Which made me wonder if open is the verb and slide is the adverb.

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Back to your sentence:

The front door slid open.

I think slid is the verb in that sentence. Why? Because that's the word I would change when I'm changing the tense of the sentence:

• The front door slid open.


• The front door is sliding open.


• The front door will slide open.

The word open functions as an adverb – we can confirm this by replacing open with other adverbs:

• The front door slid noisily.


• The front door is sliding roughly.


• The front door will slide tomorrow.