Learn Icelandic: Hittið þið þá hér? - Do you all meet them masculine here?

The verb hitta (to meet) requires the person you are meeting to be in the accusative case. þá is the masculine plural accusative pronoun, used here because you are meeting a group of males. If they were the ones doing the meeting, you would use the nominative word þeir.

How would this sentence change if we were meeting a group of women or a mixed group?

You would just change the accusative pronoun. For a group of all women, you would use þær. For a mixed group of men and women, or a group of neuter nouns, you would use þau.

Why does the sentence start with the verb Hittið?

To ask a yes-or-no question in Icelandic, you simply put the verb at the very beginning of the sentence. Instead of the statement order Þið hittið (You meet), you swap the verb and subject to make Hittið þið (Do you meet).

What is the difference between þið and þá?

þið means 'you' (plural, like 'you all') and is the subject doing the action. þá means 'them' (masculine plural) and is the object receiving the action.