A1 to start to happen or exist开始；开始进行（或存在）
The plane began to make its final descent into the airport.
Stir the sauce gently until it begins to boil.
A2 to start to do something着手（于）
The audience was becoming restless as they waited for the performance to begin.
You will begin to feel sleepy as the drug enters your bloodstream.
She cleared her throat nervously before she began to speak.
to start speaking开始说话
to have something as the first part以…开始；以…开头