speaking activity on "one & ones" asking students "Which picture (one) they prefer?";
pictures refer to usual topics such as "summer & winter" "apples & bananas" "football & volleyball";
the last slides directly address plural nouns, therefore, asking "Which ones do you prefer?" (e.g. Apple phones or Samsung phones)
the exercise was planned for an A2 level, but can be used for upper levels as well, when integrating the aspect "justifying one's decision"