Begin to do and Begin doing

We have a question : What is the difference between “begin doing” and “begin to do”? it says “Josephine began to act in movies” and then says “She began singing jazz music.” Why is there a difference?

You can say either “begin to act” or “begin acting.” They would both be correct in this circumstance. You can put an infinitive verb (such as “to act” or “to do”) after the verb begin, or a gerund (a verb that ends in -ing, such as “acting” or “doing”). However, this only works when the verb begin is in the simple present or simple past (begin, began). If it is in the present or past progressive, such as, “He is beginning” or “He was doing,” then you can only use an infinitive after the verb: “He is beginning to act on the stage” or “She was beginning to annoy (bother) me!”