auquel

In a sentence

• C'est un problème auquel je dois penser avant de répondre.

  This is a problem that I need to think about before responding.

  Here, 'auquel' means 'to which' and is used because the verb 'penser' is followed by the preposition 'à' when indicating 'to think about (something).'

• Le livre auquel elle fait référence est difficile à trouver.

  The book to which she refers is difficult to find.

  In this sentence, 'auquel' translates to 'to which' replacing 'à lequel' and indicates the object of the verb 'faire référence' which is constructed with 'à'.

• Voici le lieu auquel j'ai décidé de m'inscrire pour le stage.

  Here is the place to which I decided to sign up for the internship.

  'Auquel' here signifies 'to which' and follows the prepositional phrase 'à lequel,' used here for 'le lieu' (masc. singular).