This is to be used as a shovel

This is to be used by him

A man, like a watch, is to be valued by his manner of going.

I thought ‘to be’ was an infintive in these sentences. But I just read that they are used as auxiliaries (and that the last one is used to extend a sense of obligation…).

Can you confirm that to be are auxiliaries here, not infinitives, explain this in more detail, or give me a site to which I can refer?

Ta.

This is to be used as a shovel
This is to be used by him
A man, like a watch, is to be valued by his manner of going. 

Passive voice is comprised to the verb to be plus the past participle, so the sentences above use passive voice infinitives of use (in 1 and 2) and value in 3.

The following is from http://grammar.ccc.commnet.edu/grammar/passive.htm

Verbals in Passive Structures

Verbals or verb forms can also take on features of the passive voice. An infinitive phrase in the passive voice, for instance, can perform various functions within a sentence (just like the active forms of the infinitive).
  * Subject: To be elected by my peers is a great honor.
  * Object: That child really likes to be read to by her mother.
  * Modifier: Grasso was the first woman to be elected governor in her own right.

That’s what I thought, until I read this, which makes a bit of sense, but I’m not about to believe it. It is talking about the third sentence I showed in my first post:

The verb to be in this sentence acts as an auxiliary verb to extend a sense of obligation or duty to the observer. This makes the verb phrase similar to should be valued

Grammar should be valued only to the extent it aids in communication. Our grammar is not the same as Shakespeares’.

The verb to be in this sentence acts as an auxiliary verb to extend a sense of obligation or duty to the observer. This makes the verb phrase similar to should be valued.

That’s true in a sense, but the use of the modal simply eliminates the need for is (is to be valued vs. should be valued) and requires the use of the bare infinitive be instead of to be.

I’d go see a bare infinitive.

Dirty mind…...

It was your temptation.

My temptations go beyond gerunds and infinitives.

Would not know that from your postings.

I’m a Southerner. I’m tempted by relative causes.

We know, truly, how relative marriages go down there.

I object (directly) to that remark. I would never marry my cousin, but her sister looks pretty good.

May, you’re really reaching today. Hope you make a funny sometime.

I think your humors are out of balance. Get some leeches for that flu.

My humours are just fine.  The flu does not influence them.  It is what is coming at me that needs swatting, like a fly.