Ye also (κα υμεις). Ye Gentiles (now Christians), in contrast to ημας (we) in Ephesians 1:12.

In whom (εν ω). Repeated third time (once in verse Ephesians 1:11, twice in Ephesians 1:13), and note ο or ος in Ephesians 1:14.

Ye were sealed (εσφραγισθητε). First aorist passive indicative of σφραγιζω, old verb, to set a seal on one as a mark or stamp, sometimes the marks of ownership or of worship of deities like στιγματα (Galatians 6:17). Marked and authenticated as God's heritage as in Ephesians 4:30. See 2. Corinthians 1:22 for the very use of the metaphor here applied to the Holy Spirit even with the word αρραβων (earnest).

Spirit (πνευματ). In the instrumental case.