Do I have to use the auxiliary before all the verbs?

Question

Which of the following is correct?

1. I will dance and sing at the concert tonight.
2. I will dance and will sing at the concert tonight.

Does it happen with to, too? For example:

1. I like to play soccer and watch TV on weekends.
2. I like to play soccer and to watch TV on weekends.

Answer 1

There are different types of constituent structures that can be conjoined by and. All of these different points of conjunction are valid, and they all fundamentally mean the same thing:

1. [I like to dance] and [I like to sing].
2. I [like to dance] and [like to sing].
3. I like [to dance] and [to sing].
4. I like to [dance] and [sing].

(To answer your question about to, as you can see it does happen.)

Usually, people naturally conjoin as far down the above list as possible, for the sake of brevity. For example, the content might force you to stop at sentence (2):

• I [like to dance] and [hate sitting].

However, repeated information in a sentence is never incorrect on its own. One might choose to include some redundant parts for the sake of clarity, for emphasis, or for aesthetic reasons (e.g. it sounds better or fits better metrically). This can be appropriate both formally and informally, and is done by everyone in certain situations.

(If you made sentences like 1-3 all the time, where it is not necessary, it would probably come off as odd though. As I said, usually the briefest version possible is chosen.)

Answer 2

The position of the adverb makes all the difference:

"I will dance and sing at the concert tonight" -- the adverb is modifying the sentence, and therefore both verbs (dance and sing).

"I will dance and will sing at the concert tonight" -- the adverb may only be attached to the verb closest to it (e.g. "I will dance for the next half hour, and sing at the concert tonight").

The same goes for your other example, where the timing of the first verb is similarly unclear.

Put the adverb at the beginning of the sentence, and the problem goes away:

"At the concert tonight, I will dance and sing."

Answer 3

Because there is an "and", it pairs the verbs up together, so the auxiliary applies to both automatically.

This is only because the same auxiliary("will", or the "to" are being used for both.) is being used.

For adjectives, there can be different adjectives, not necessarily the same one,

I.e.

To all the strong fathers and mothers.

Unless you would like to specify that the mothers have a different characteristic i.e. beautiful, the "strong" applies to both.

To all the strong fathers and strong mothers.

Answer 4

There are two approaches to grammar:

1. Grammar rules are bible, thus people should adjust themselves to those rules.
2. People say whatever they feel natural (language evolution), and grammar rules should be adjusted to the public's speech patterns.

My personal experience is that the second approach is much more closer to the reality, as I haven seen it in English, Persian, French and Esperanto. They all have some grammatical rules, but many times you encounter someone saying something ungrammatical, while sounding natural. Based on this reason, these sentences seem more natural to me:

I will dance and sing at the concert tonight.
I like to play soccer and watch TV on weekends.