used to attribute to the known object a characteristic that helps one know more about the topic; may optionally be followed by jest [+nominative]
used to juxtapose elements that are equivalent
used to indicate that the subject of the conversation has peculiarities which are familiar to the interlocutors, so that nothing else needs to be said about it in order to understand the topic
in that case, then (used in if-constructions)

used to indicate what one is talking about
used to indicate what can be said about the topic, in contrast to all that cannot be said about it
so (used after a pause for thought to introduce a new topic, question, or story, or a new thought or question in continuation of an existing topic)
used to indicate that the topic in the relevant question refers to a known set of elements from which a choice has to be made
used to express surprise that something is indeed like that as the speaker did not think it could really be so
used to indicate that the topic refers to a known object, mentioned in the preceding statement
(colloquial) used to indicate that what someone has said about the topic is a fait accompli and should no longer be discussed