Tanit“But I'm stuck with a sentence where "to do" is replaced by "not to do":
a1) I suggest not doing X. (I reckon this is fine)
a2) I suggest not to do X. (???)
b1) I suggest [that] Y shouldn't do X. (I reckon this is fine)
b2) I suggest [that] Y [not do | don't] X. (this sounds terribly bad!)”
Your questions stem from the use of the mandative subjunctive, which arises in turn from the use of the verb "to suggest." However, you've complicated things by using the complicated predicate "to do X" in your sentences' subordinate clauses. I'm assuming that "Y" always represents a personal pronoun (or proper noun), but "X" could be either a demonstrative pronoun (or regular noun in certain cases) or a verb depending on your meaning.
a1) This construction is fine if "X" is a demonstrative pronoun, but incorrect if represents a verb.
a2) This construction is incorrect. If "X" is a demonstrative pronoun, the verb "to do" must be changed from the infinitive to the subjunctive and a personal pronoun added so that the sentence reads
I suggest Y not do X. This makes the subordinate clause a content clause, which means that the word "that" could be added as you've done in example b2). The sentence will not work at all if "X" is a verb.
b1) While this construction is not grammatically incorrect, it can sound too passive when "suggest" and "should" are in close proximity. Anyway, that's assuming that "X" is once again a demonstrative pronoun. This construction will not work if "X" is a verb.
b2) It may not seem like it, but switching between "not do" or "don't" (i.e. "do not" ) dramatically changes this sentence. They cannot be used interchangably in this context. As I mentioned above, the "not do" construction works fine if "X" is a demonstrative pronoun. However, if "X" is a (subjunctive) verb then "do not" or "don't" (or does not/doesn't for singular third person pronouns) must be used.
I apologize if this sounds complicated, but it's a result of using an auxiliary verb in your example predicates. If you replace "to do X" with a simpler verb it would probably be clearer. Basically, your two options are to follow the verb "to suggest" with either a gerund or the subjunctive. Either way, the word "not" would precede the dependent verb should you choose to make it negative. Looking ahead, I've used the verb "to interview" in an example of each construction.
Gerund:
I suggest (not) interviewing...
Subjunctive:
I suggest (that) he (not) interview...
Here's the sentence I'm trying to write (it's for a research paper):
1. "Issues of availability, together with constraints on time and scope of the research, suggested not interviewing any member of the scientific committee."
2. "Issues of availability, together with constraints on time and scope of the research, suggested not to interview any member of the scientific committee."
3. "Issues of availability, together with constraints on time and scope of the research, suggested that no member of the scientific committee should be interviewed."
I'd go for no. 1 (no. 3 seems to carry a different meaning ... or am I wrong?), but I am not sure about that. What do you think?
I'm also trying (with little, if any, success) to work out the general pattern.”
Both the first and third examples work. The first is the gerund construction, the third is the subjunctive construction. The second is incorrect. However, despite being technically correct, both the first and third examples still sound awkward. Ultimately, I think this is because it sounds strange for "issues" to suggest something directly. Typically they would suggest something
to someone. For instance, I think that "Issues of availability... suggest not interviewing any member of the scientific committee to me" or "Issues of availability... suggest to me that no member of the scientific committee should be interviewed" both sound better.