d'accord unit 5 Stem-changing verbs in -er

What two forms of stem-changing verbs remain unchanged?

In verbs like emmener, the -e- before the ending changes to what for all subjects (excluding nous and vous)?

In verbs like espérer, the -é- changes to what for all subjects (excluding nous and vous)?

Conjugate the verb for the subject: je / acheter

Conjugate the verb for the subject: Marie / préférer

Conjugate the verb for the subject: Vous / promener le chien

Conjugate the verb for the subject: tu / amener ton frère

Conjugate the verb for the subject: ils / acheter des cahiers

Translate: You all hope

Translate: I hope