To begin to cry; to start crying (used when someone, often a baby, starts to shed tears).
赤ちゃんが夜中に急に泣き始めた。
The baby suddenly began crying in the middle of the night.
映画の最後の場面で彼女は泣き始めた。
She began to cry at the final scene of the movie.
試験の結果を見て泣き始める学生もいた。
Some students began to cry when they saw the exam results.