"I am afraid that my son does not remember his grandmother."
Translation:Ho paura che mio figlio non ricordi la nonna.
"ricordi" is present subjunctive form of the verb "ricordare" for 1. 2. and 3. person singular https://en.wiktionary.org/wiki/ricordare#Conjugation
Subjunctive is used in secondary clauses when they are introduced with "che". http://www.italymagazine.com/community/post/italian-lesson-when-use-congiuntivo-subjective