nous nous is used with reflexive verbs and means ourselves
nous lavons : we are washing
nous nous lavons : we are washing ourselves
"sommes-nous ..." means 'are we ..' in French.
Sommes-nous .... means 'are we ...' in French.
It means 'We are'
our
Nous avons ensemble means "we have together..." in French.
nous avons = we have [nous] n'avons [pas] = [we] don't have [any, no]
we love you
(nous) allons means '(we) are going. (Nous) allions means (we) went.
Nous sommes means 'we are' in English.
'nous mettons' is 'we put' in French. Nous mettons nos habits means we are putting up our clothes.
Literally "Pourquoi sommes-nous parler français" reads as "why are we to speak French". If you mean "why should we / why do we have do speak French", this is: "pourquoi devons-nous parler français".
In French it is: Contactez-nous