Please, tell me that I have English! Small questions

[Globetrotter]

Sometimes I feel that I have NO English at all; some of my friends ask me some questions which I think that I know, but when I first start answering, I find that I ,simply, have no answer, although I 've passed many grammar courses with A's. Anyway, this is one of them:

How to put the following question into passive

The question is
How do you do?

.............................................................
Another problem
Just tell me that I'm right when saying that the following sentence is wrong:
"He is not accustomed to getting up early"
Is it okay for -ing to be after "to"?
..............................................................

Another ambiguity is in the following sentence:
"He need never feel lonely"
Where is need's (s)?

Thanks in advance

[Dozy]

"How do you do?" is a set expression -- a type of greeting. I do not see any meaningful way to put it in the passive, nor any reason to want to.

"He is not accustomed to getting up early" is correct. "getting up early" is a noun phrase. Grammatically the sentence is like "He is not accustomed to the climate", for example.

In "He need never feel lonely", the verb "need" is behaving as an auxiliary verb, so it does not inflect. It's a similar idea to "He must never feel lonely", for example, where "must" does not become "musts". However, unlike "must", the verb "need" has a more common main-verb use in which it does inflect (e.g. "He needs money").

[Globetrotter]

Actually, "thanks" is unable to express my gratitude. Anyway, I'm sorry to ask but I would like to know your job, teacher, prof, and in what major? And are you a native speaker? British or American?
Finally, what is the best grammar course you suggest for a non-native to study -or to buy- ?

[Dozy]

I'm a native BrE speaker. I'm not actually a teacher, just someone with an interest in language. I do not feel qualified to advise you on grammar courses; perhaps someone else here might be able to make some suggestions?

[Jaro7788]

[Dozy]

Re-reading my quote, I notice also that I should have mentioned that it is a modal auxiliary verb, rather than just an auxiliary verb. Obviously some auxiliary verbs, such as "do" and "have", do inflect.