Do subordinating conjunctions subordinate clauses with verbs only?

Question

1. While in Rome, John took a lot of pictures.

2. While he was in Rome, John took a lot of pictures.

3. Although on vacation, John calls the office often.

4. Although he is on vacation, John calls the office often.

5. Many people have a disinclination to recognize the weakness of their analytical skills while willing to admit their lack of computer skills or other technical skills.

6. Many people have a disinclination to admit fault while recognizing that they can’t possibly be in the right all the time.

Both While and Although are subordinating conjunctions, I am confused whether they should be followed by a full clause (with verb) or not.

Which one of the above examples are incorrect? I have seen many "while +ing," modifiers whereas Although must be followed by a clause which has a subject and a verb. Is that correct?

Which subordinating conjunctions (as in ON A WHITE BUS mnemonic) must be followed by a clause with verbs and which ones are more flexible?

Excuse my English - not a native speaker.

Answer 1

The following is my initial attempt to answer your final question.

Y = can be reduced
N = can't be reduced
? = some people may allow a reduced form
S = some reductions but not others seem allowable
Q = would seem to be reducible, but not by simple elision of a form of be

only if (Y)

• only if he is taking his tablets
• only if taking his tablets

now that (N)

• now that he is taking his tablets
• now that taking his tablets

after (Q)

• after he is taking his tablets
• after taking his tablets

although (Y)

• although he is taking his tablets
• although taking his tablets

as (N)

• as he is taking his tablets
• as taking his tablets

when (Y)

• when he is taking his tablets
• when taking his tablets

whereas (N)

• whereas he is taking his tablets
• whereas taking his tablets

while (Y/S)

• while he is taking his tablets
• while taking his tablets

whenever (?)

• whenever he is taking his tablets
• whenever taking his tablets

wherever (S)

• wherever he is taking his tablets
• wherever taking his tablets

whether or not (S)

• whether or not he is taking his tablets
• whether or not taking his tablets

in case (N)

• in case he is taking his tablets
• in case taking his tablets

if (S)

• if he is taking his tablets
• if taking his tablets

though (Y)

• though he is taking his tablets
• though taking his tablets

even though (Y)

• even though he is taking his tablets
• even though taking his tablets

even if (Y)

• even if he is taking his tablets
• even if taking his tablets

before (Q)

• before he is taking his tablets
• before taking his tablets

because (N)

• because he is taking his tablets
• because taking his tablets

until (Q)

• until he is taking his tablets
• until taking his tablets

unless (Y)

• unless he is taking his tablets
• unless taking his tablets

since (Q)

• since he is taking his tablets
• since taking his tablets

so [that] (N)

• so [that] he is taking his tablets
• so [that] taking his tablets

This is, as I say, an attempt. Others may find it needs correcting / adjusting.

Answer 2

Whilst accepting what John Lawler says, I can't agree with your suggestion re 'although'.

'Although ill, he went to work' or

'Although 90 years old, he runs marathons',

are perfectly everyday grammatical expressions.