Acts 2:4 And they i.e., the apostles were all filled with the power of the Holy Spirit and began to speak "the mighty accomplishments of God," See verse in different languages, as the Holy Spirit gave them the ability.

AUV⁽ⁱ⁾ ⁴ And they [i.e., the apostles] were all filled with [the power of] the Holy Spirit and began to speak ["the mighty accomplishments of God," See verse 11] in different languages, as the Holy Spirit gave them the ability.