Optional or Obligatory adverbials ?

[hela]

Dear teachers,

Would you please tell me if all the following adverbials are optional?
It is true that if omitted they wouldn't affect the structure of the sentences, but wouldn't they change their meaning?

1) He saw the movie twice on Saturday.

2) Some students turned out quite good in the test.

3) Yesterday was the happiest day of the year for me.

4) Will they be able to move the belongings by themselves?

Many thanks and I wish you all a merry Christmas.

 

[Tdol]

You could remove them and still have functioning sentences in context, but the meaning would be affected. In 2), I would definitely use well instead of good, and would say something like did well in the test.

Merry Christmas ;-)

 

[hela]

Thanks, Tdol

So would you say that "twice", "on Saturday", "in the test", "for me" and "by themselves" are all optional adverbials even though they affect the meaning of each sentence?

I wish you all the best and a very nice evening.

 

[Barb_D]

The sentences remain grammatical, but the meaning changes significantly, when you remove them.

 

[hela]

Good evening, Barb_D

So what is the answer, please ? Are they considered optional or obligatory? I read that obligatory adverbials are "adverbials that render a sentence ungrammatical and meaningless if removed", which is not the case in all the above sentences. So I'm lost.

Wish you all the best

 

[Barb_D]

The sentence remains grammatical and has meaning without them.

It is, however, a different meaning than with them.

If you definition is "there is no meaning at all" or "the sentence is ungrammatical" then I guess they are optional.