Past simple-present perfect confusion involves the confusion of two English aspectual tenses, the past simple and the present perfect, which are both used to talk about events in past time. EFL learners may inappropriately use either of these.
The primary distinction in meaning is that past simple is used for finished time whereas the present perfect is used for unfinished time.
An additional complication however is that British English and American English differ. Americans use the past simple in circumstances that are inappropriate in British English.
The past simple is usually taught and acquired before the present perfect. As such, learners may make attempts using the past tense when present perfect is more appropriate.
Conversely, learners with a romance language as their L1, particularly French, may over-use the present perfect as the French equivalent is used as a general past tense in French.