Sometimes parsing reveals that some phrases, words, and even whole sentences are not part of the parsed sentence. They are called "introductory constructions" and are not grammatically related to the rest of the words, unless in meaning.
For instance:
- Apparently, they were elves.
- Probably the whole palace is made of glass.
In the first example, "apparently" is an introductory construct. Its meaning in this sentence - all the signs said that ... In the second example, the introductory word is the adverb "probably" in the meaning - I'm not sure that ...
All introductory structures have certain signs:
- It is difficult to ask a question from the members of the proposal.
- You can replace them with other introductory words or expressions that are appropriate in meaning.
- You can remove them from the proposal without violating the basic meaning.
In terms of introductory constructions can be divided into various groups:
- Conviction or doubt. For example: it goes without saying, indeed, of course, obviously, undoubtedly , probably, it seems, perhaps, I think, perhaps, I hope, etc.
- Source of a saying or statement. For example: they report, according to ..., according to ..., say, in your opinion, in your opinion, in my opinion, etc.
- Expression of emotions. For example: fortunately, unfortunately, it’s a sin to hide, to trouble, to joy, to surprise, etc.
- The order of events, statements. For example: so, firstly, in general, in particular, in the end, and so on.
- Attracting the attention of the interlocutor. For example: listen, you know, understand, imagine, please believe, see, etc.
- Evaluating the style of expression or utterance. For example: in other words, so to speak, in one word, so to speak, in other words, etc.
You must also know that many of the above words may appear in the sentence as introductory constructions, but may not be them. For instance:
In April, there may still be frosts.
The introductory word is comma-separated and is not a member of a sentence.
In April, the temperature will rise, but its decrease is also possible.
In the following example, the word “maybe” is not introductory; it is part of a compound predicate and is not highlighted by commas.
Introductory constructions also should not be confused with words that do not stand out with commas. Most often they are adverbs. For example: all of a sudden, supposedly, as if hardly, exclusively, even, hardly, in the long run, even, as it were, once, resolutely, almost, approximately, little by little, just, etc. But the word "used to be" is a particle and stands out on one or both sides with commas, if it is in the middle of the sentence.
To identify introductory words and constructions, it is necessary, firstly, to look for them in the group of the above words, which are not introductory. Secondly, you need to try to put questions to them from the members of the proposal. If it does not work out, then these are introductory words. Thirdly, you can remove them from the sentence and check if the meaning has changed. If it has not changed and it is possible to replace it with a synonymous expression, then these constructions are introductory, and you can safely mark them with commas.
Introductory constructions in English, as well as in many others, perform the same functions as in Russian. They are also not members of the proposal, and questions cannot be posed to them. True, unlike Russian introductory words, English is not distinguished by commas.