The present participle is formed by adding "-ing" to the infinitive and it indicates an acton happening in the present, such as: “The girl is swimming” or “I am thinking.”
The past participle usually ends in "-ed" (for regular verbs) and it indicates a completed or past action: “The shop was closed" or "The teacher had spoken."
Participles may also function as adjectives, such as, “Your girlfriend is a charming person.”
A dangling participle is one that is not clearly connected to the word that it modifies, for example: “Standing at the corner, two children walked past me.” This is clumsy grammar and should be avoided as it can give the impression that the children walked past you while they were standing at the corner.
A better way to say this would be, “While I was standing at the corner, two children walked past me.”