Image forming system and image forming apparatus with voice instruction to reform print setting operation

An image forming apparatus comprising:

• a display panel;
• a voice inputter that receives an instruction by voice;
• and
• a hardware processor that:
• analyzes a voice content that has been received by the voice inputter;
• determines whether a setting of one of a plurality of adjustment functions preliminarily provided in the image forming apparatus has been input based on an analysis result of the voice content;
• determines whether the voice content contains an input of a setting value of the one of the plurality of adjustment functions that has been determined to be input;
• and
• displays a selection screen on the display panel based on a result of a determination that the setting of the one of the plurality of adjustment functions has been input but the voice content does not contain the input of the setting value of the one of the plurality of adjustment functions that has been determined to be input,
• wherein the selection screen comprises a setting candidate in which the adjustment function has been adjusted in accordance with the setting value as a preview image.