▲be happy + to do sth.
I am very happy to receive your kind invitation. 我失分高兴受到您的盛情邀请。
注意：许多形容词、副词、过去分词作表语时，后面带有不定式作状语，表示产生这种情绪的原因等。常见的这类词有：able, angry, anxious, afraid, clever, determined, eager, fit, foolish, cruel, glad, lucky, sorry, pleased, ready, willing, happy, shocked, fortunate, surprised, disappointed, free, sure, pround, careful, delighted等。再例：
You are sure to succeed.
I am glad to meet you again.
He jumped with joy to learn his son had passed the exam.
Everybody should always be ready to help others.
Be careful not to catch cold.
▲be happy + -v.ing / v.-ed
She was happy sitting among her students. 坐在学生中间很高兴。
I’m very happy married to you. 跟你结婚我很幸福。
The boy was very happy given a present. 因为得到了礼物，这歌男孩非常高兴。