Can the following sentence (without if) be regarded as a conditional type 2 sentence?

Question

I was wondering if the following question can be regarded a conditional sentence of the 2nd type:

To hear some men talk, you'd think that women belonged to a different species!

In fact the sentence can be:

If you heard some men talk, you would think that women belonged to a different species!

My 2nd question is about belonged. Why do we say

To hear some men talk, you'd think that women belonged to a different species!

and not

To hear some men talk, you'd think that women belong to a different species!

why do we use past tense for thought of the person?

Answer 1

No, it would not generally be considered a second conditional because the protasis is not in the correct form. It should be in the subjunctive II (often called "past subjunctive") mood.

If you heard some men talk, <-- subjunctive II

To hear some men talk, <-- not subjunctive II

However, you might still consider this sentence conditional, because there is no authoritative definition of what constitutes a conditional sentence.

As for your other question, the rest of the apodosis (after the usual "would" / "could" / "might" portion) is normally in the past tense. I suspect that the reason is to match the protasis, since the subjunctive II is usually identical to the past tense form.

(Note that some people will use different terminology to explain this.)