I made some mistakes in the test.
Watashi wa tesuto de ikutsu ka machigaeteshimatta.
I; me; private affairs; personal matter; secrecy; selfishness
topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis
indicates location of action; at; in; indicates time of action; indicates means of action; cause of effect; by; and then; so; indicates continuing action; indicates certainty, emphasis, etc.
how many?; how old?
indicates a question (sometimes rhetorical); or; whether or not; some- (e.g. something, someone); indicates doubt, uncertainty, etc.; emphatic prefix; suffix forming adjectives or adverbs; in that way
to make a mistake (in); to commit an error (e.g. in calculation); to confuse; to mistake something for something else