I was reading Harry Potter and the Philosopher's Stone and then I happened to notice something like this:

The mountains around the school became icy grey and the lake like chilled steel.

I understood it as "the lake was like chilled steel" though the auxiliary verb had been omitted. I remembered catching several other occasions of this. One example is:

'I'll be back at dawn,' said Filch, 'for what's left of them,' he added nastily, and he turned and started back towards the castle, his lamp bobbing away in the darkness.

The auxiliary verb seemed to be missed intentionally in the last phrase of the sentence, as I read it as "his lamp was bobbing away in the darkness."

I just wonder if this is grammatically correct? Is there any difference between having the auxiliary verb and omitting it in these cases? Is there any special meaning by omitting the auxiliary verb in these scenarios?

1 Answer 1


In the first example, the verb “became” is also referring to the lake. In this case, when using a coordinating conjunction, if one does not put a comma, it is perfectly fine to skip the verb, meaning the first verb applies for the second part of the sentence.

A simpler, more familiar example would be:

“The boy ate the apple and the banana. “

It is needless to say

“The boy ate the apple and the boy ate the banana.”

Similarly, if the subject is to change, we can still omit the verb and mention the new subject:

“The boy ate the apple and the girl the banana” in the same style as the Harry Potter quote.

The 2nd paragraph is a different situation. The sentence “his lamp bobbing away into the darkness” is a modifier for Filch. In this situation, it is the equivalent of saying “with his lamp bobbing away into the darkness”. The modifier is not a complete sentence, it is an incomplete prepositional phrase. Here the linking conjunction/preposition is omitted, but the modifier is still a phrase, meaning it is not a complete sentence with a subject and a verb. “Bobbing” is a participle adjective describes the lamp, and is not a verb for the “lamp”.

In conclusion, since both examples are incomplete phrases that rely on what comes before them, they do not need to have a subject and a verb. The first example has an implicit verb from the part before it, while the second example doesn’t have a verb since it is a modifier phrase, and is incomplete.

  • 1
    Became is a lexical verb, not an auxiliary verb, so no auxiliary has been omitted in the OP's example.
    – user230
    Jul 14, 2018 at 8:38
  • How about this one from The Witcher: "It was late afternoon and the ropers', saddlers' and tanners' stalls were already closed, the street empty." There was a comma and I don't think the last phrase is a modifier for the stalls, or is it?
    – Hiếu
    Jul 20, 2018 at 21:03

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .