This is where a few basic Chinese concepts come in handy:
- Spoken Mandarin is genderless, written Chinese has Gender expressed in the radicals
- Knowledge of radicals will tell you the appropriate
Tā to use
I like using yellowbridge.com for looking up etymology, stroke order, radicals, etc. for each character: http://www.yellowbridge.com/chinese/character-etymology.php?zi=%E7%89%A0
他 The radical, 人, makes this pronoun for
她 The radical, 女, makes this pronoun for
祂 The radical, 示, make this pronoun for
它 were merged together.
牠 refers to animals, as you can tell by the radical 牛 (cow). And
它 refers to inanimate objects.
们 men makes the subject/noun plural.
So, in the context of your sentence,
No they don't; they only sell stationary, you would use