How "Is + verb" possible?

Question

We can use a full infinitive or a gerund as a complement of the 'be'-verb. For example,

The first thing I do in the morning is to check my mobile phone.

The first thing I do in the morning is checking my mobile phone.

But I've seen the bare infinitive used in such construction with no real difference:

The first thing I do in the morning is check my mobile phone.

Thus, bare infinitive is used when the finite element of the first verb is a form of "do" : Using bare infinitive after 'does'.

Now, my question is whether it's a case of elision, such as "The first thing I do in the morning is [that I] check my mobile phone." or is there any other grammatical explanation?

Does this answer your question? Using bare infinitive after 'does' — Cardinal, Jun 05 '20 at 06:16
@Cardinal, that question tells about using bare infinitive after 'does'. But I want to know whether it's a case of elision :"The first thing I do in the morning is [that I] check my mobile phone." — Sandip Kumar Mandal, Jun 05 '20 at 08:50
the case of bare infinitive is just a form of what people usually call "spoken English", which is normally seen in casual communication. It is non-formal so it does not have to be grammatically correct. — Lê Gia Lễ, Jun 05 '20 at 09:28
@LêGiaLễ: your comment strongly implies that it is not "grammatically correct". On what do you base that conclusion? — Colin Fine, Jun 05 '20 at 15:54

score 2 · Answer 1 · answered Jun 05 '20 at 13:01

The first thing I do in the morning is check my mobile phone

This is perfectly grammatical and perhaps the most common. When the subject has a form of "do", the infinitive is used. You can put "to" there, but it is optional.

The first thing I do in the morning is checking my mobile phone

The sentence above is not grammatical. It'll only be grammatical if the verb "do" is progressive as in:

The first thing I was doing was checking my mobile phone.

How "Is + verb" possible?

1 Answers1