, a combination of する and the conjunction particle
と, is generally considered to be an abbreviation of そうすると
, and means that 'once (A) is done, (B)', or 'upon (A), (B)'. すると
is usually used at the beginning of a new sentence, to highlight something that occurred due to the circumstances mentioned in the previous sentence/statement.
As a standalone statement, すると
is classified as a conjunction
I cleaned my closet for the first time in a long time. Upon that, I found clothes that I thought I had lost.
An old lady was washing her clothes in the river. Just then, a peach flowed down the river from a distance.
The 'result' that すると
conveys, should always be one of two specific things. Something that the speaker has no control over, or a conclusion/determination that the speaker wants to confirm is correct (based on their understanding of the previous statement).
I gave a banana to a monkey. Having done that, more and more monkeys started to gather around me.
You are 19? So you mean to say that you are a freshman, right?
is used to draw a conclusion about another person's statement, the translation is closer to 'so you mean to say (A)', or 'if so, then (A)'.