Look at the dictionary entry.
be•gin (bi gin′)v.be•gan, be•gun, be•gin•ning [ME beginnen; before 1000]1 to do the first part: begin your work2to bring into being; originate: The brothers began the business while still in their teens.
Which tells you the forms of the verb?

[ME beginnen; before 1000]
be•gan, be•gun, be•gin•ning
1 to do the first part 2to bring into being; originate
(bi gin′)

Question

Look at the dictionary entry.
be•gin (bi gin′)v.be•gan, be•gun, be•gin•ning [ME beginnen; before 1000]1 to do the first part: begin your work2to bring into being; originate: The brothers began the business while still in their teens.
Which tells you the forms of the verb?
 	
	[ME beginnen; before 1000]
	be•gan, be•gun, be•gin•ning
	1 to do the first part  2to bring into being; originate
	(bi gin′)