What is the equivalent in English of the French sentence part "complément de phrase"?

In French, a sentence has two essential syntactic parts (the subject and the predicate) and may have one or more "complément de phrase", which are optional parts.

"complément de phrase" = "sentence complement" (literal translation)

(Nuances and details could be added to that explanation in an advanced grammar and syntax context, but let's keep it simple.)

I tried looking for the equivalent in English of that syntactic function, the "sentence complement", but grammar sources I found contradict each other and don't define a specific syntactic function, but different sub-fonctions (functions held by grammatical groups within the three main syntactic groups (subject, predicate and "sentence complement"). Maybe I'm only stuck in my French grammar point of view. Therefore, I'll explain the "complément de phrase" so you can tell me what it refers to.

The "complement de phrase" syntactic function is usually held by an adverbial group, a prepositional group, a nominal group or a "subordinated sentence".

• Adverbial gr. : Very carefully, he opened the cage.
• prepositional gr. : With all due respect, I must refuse your offer.
• nominal gr. : I ate cereals this morning.
• "subordinated sentence" : While he was asleep, someone stole his ring.

Here are the characteristics of a "complément de phrase":

1. optional/removable

   Very carefully he opened the cage. (Sentence still works = OK)

   While he was asleep someone stole his ring.(Sentence still works = OK)

   X *While he was asleep, someone stole his ring. (Sentence not OK, the predicate is incomplete, so "his ring" is not a "sentence complement", but a direct object complement of the verbe stole.)

   X While he was asleep, someone stole his ring. (Sentence not OK, the predicate is incomplete = "his ring" is not the "a sentence complement", but a direct object complement of the verbe stole.)

2. movable within the sentence (usually before/after the subject/predicate/other "sentence complement rather than inside them")

   Very carefully, he opened the cage.

   He opened the cage very carefully.

   ? He very carefully opened the cage.

   X/? He opened very carefullly the cage.

3. "non pronominalisable" = "cannot be replaced by a pronoun" (except for "location complements" that can be replaced by the pronoun "y", but that is probably only specific to French).

   X Very carefully It, I opened the cage. (wrong sentence = Ok, the )

   Very carefully, I opened the cage it. ("The cage" can be substituted with a pronoun, "it", since it is the direct object complement of the verb "opened".)

4. detachable (can be isolated)

   I ate cereals and that took place this morning Someone stole his ring while he was asleep.

Now that you understand better the "complément de phrase", can you please tell me what is its English equivalent and if there are differences between the French and the English concept?

Solution 1:

Ok, here's the best I can come up with, although it may not be a perfect match. (I'm a bit confused about your first example from characteristic 4, because English treats the first sentence as two independent clauses joined by a conjunction.)

It appears to me that English distinguishes three kinds of the "complément de phrase" without giving them a common name. The three kinds are adverbs, adverbial clauses, and adverbial phrases. The distinction between the last two is that the clause, while subordinate, has both a subject and predicate, whereas the adverbial phrase lacks at least one of these items.

Many prepositional phrases are also adverbial phrases (e.g. in the town), but I'm not sure whether all of them can be classified as such. For example, prepositional phrases that are used to indicate indirect objects or possession may not be considered adverbial. If such prepositional phrases are not considered to be adverbial, then, adverbial phrases and clauses along with adverbs seem to match the French category of "complément de phrase" pretty well.

With regard to characteristic 3, note that location adverbs and phrases can cometimes be replaced by words like "here" and "there," which function in a way that is similar to a pronoun.

Solution 2:

I believe they're called adjuncts in linguistics.

Here is a link to the Wikipedia article.

Prima facie, they meet your characteristics. You'll have to wade through the details to see if they match up with the French concept.