HSK 4
通
tōng动形（量）
to go through; to know well; (suffix) expert; to connect
他的电话终于打通了。
Tā de diàn huà zhōng yú dǎ tōng le.
His phone call finally went through.
Say it
Hold the button, say it, then let go.
Other HSK words sharing a character
Also free:
Appears across levels (4（7-9）) in the HSK 3.0 word list.