For your information, pants (or trousers in British English) is always plural; in full it would be "a pair of trousers" (probably due to it entirely being two pieces of fabric stitched together. It's a similar thing with shorts (un short) and scissors (des ciseaux) which is plural in both English and French
Pants in English is derived from a pair of leggings which later became joined to form a single garment. After the Norman conquest the British adapted the French pantalon to describe what they regarded as a pair of connected leggings. Of course, the French used pantalon then, as they do now, as singular because they are referring to only one unit of clothing.
Thus English pants and connected words are rendered plural and the French pantalon and related modifiers etc are given as singular.
In English, we only use the plural 'my pants'. I think, technically, they consist of two pant legs, so that's why we often say, for example, 'a new pair of pants' and not 'a new pant'.
If we have more than one of this type of clothing, we would say 'my pairs of pants', which I think in French would be 'mes pantalons'.
He/She/It is third person singular therefore he/she/it has. French mon pantalon is singular but English translation is my pants plural because that is how English treats pants.
French pantalon singular. English pants plural. Because the English translation is plural it is third person plural. Therefore it is they have not he/she/it has.
Yes and no.
No in the sense that avoir only conjugates to a in the third-person singular, and in English the third person singular is "has" and only "has." Yes, in the sense that you might run into the odd case like this one, where you're required in English to switch from third-person singular to third-person plural, which is "have," because of the quirky noun.
mon pantalon a une poche. Ok, which is it? "Has" or "Have" for "a" in french. I just translated one similar to this one and the answer was " has". Now I translated this one using "has". But, now the correct translation for "a" in french is have. J'ai pense ca "a" is avoir en francais pour exemple ( elle, il, on a).
It depends on whether the noun is treated as singular or plural in English. Normally, the singular in French is going to be singular in English too, resulting in "has," but this is not the case with "pants," which is plural in English even when talking about only one pair. Since plural nouns use "have" that, in effect, becomes the translation for «a» in this case.