Mark 3:11

The unclean spirits [τ α]. The article indicating those particular spirits which took part in that scene. Mark's precision is shown in the use of the two articles and in the arrangement of the noun and adjective : The spirits, the unclean ones.

When they saw [ο τ α ν ε θ ε ω ρ ο υ ν]. More accurately as Rev., whenever they beheld. The imperfect tense denotes a repeated act. The an in otan gives an indefinite force : as often as they might see him.