Ablative Grammar Help!

Ablative of Separation
Nouns used with accompanying prepositions of ab/ā/abs, “from”; ex/ē, “out of”; or dē, “down from”.
E.g. ex agrīs, “from the fields”

 Ablative Absolute
The circumstances surrounding an action.
E.g. Urbe captā, Aenēās fūgit, “With the city having been captured, Aeneas fled.”

Ablative of Origin or Source
A type of ablative of seperation, but it is used ( without a preposition like: a, ab, e, ex, etc.) with verbs (with past participles) indicating origin, descent, or source:
E.g. nātus genere nōbilī  “born from a renowned family” — i.e. ‘of a renowned family’

Ablative of Instrument or Means
The means by which an action was carried out.
E.g. oculīs vidēre, “to see with the eyes”.

 Ablative of Agent
The person or object that does a deed.
E.g. rex a militibus interfectus est “the king was killed by the soldiers” with personal agents, but impersonally it reads rex armis militum interfectus erat “the king was killed by the weapons of the soldiers.”

Ablative of Time “When” or “Within which”
The time when or within which an action occurred.
E.g. aestāte, “in summer”; eō tempore, “at that time”; Paucīs hōrīs id faciet, “within a few hours he will do it.”

Ablative of Comparison
The the second object being compared, Y is bigger than X, is put in the ablative.
E.g. Haec via longior illä est. This road is longer than that one.

Ablative of Degree of Difference
This is very similar to ablative of comparison, but there are not two objects being compared, but only one word of measurement (little, big, small, few, great,etc.) in the ablative
E.g. Paulö post discëssit. He left a little later. (“afterward by a little bit”)

Ablative of Specification or Respect
Sometimes, the ablative is used to specify in what respect a statement may or may not be true.
E.g. Rex nomine erat. He was king in name (only).

The Locative Ablative
With the names of cities (Rome, Athens, Sparta, Brundisium, Alexandria etc) and small islands (Sicily, Crete etc.), the prepositions ad, ab and in are not used
Places from which: name in the ablative without ab.
E.g. Brundisio- from Brundisium      Athenis- from Athens
Sicilia- from Sicily
Place in which- this is the locative, and rules vary. (First and second plural, plus third plural- use the ablative)
E.g. Athenis- in Athens, at Athens
Sardibus- in Sardes, at Sardes

Ablative of Cause
The ablative is often used to explain why something is done, or its “cause.”
E.g. Hoc fëcï amöre vestrï. I did this from (out of, because of) love of you.

Ablative of Description
A noun in the ablative, accompanied by an adjective, can be used to describe the qualities by which a person is characterized. This is sometimes combined with Ablative of Source or Origin.
E.g  Diodōrus, uir summā grauitāte, maximē īrātus est. “Diodorus, a man of the utmost dignity, became extremely angry.”
E.g senex cānīs capillīs et ueste sordidā  “A man with white hair and unclean garments”

The Ablative of Price
An ablative used to indicate the resources (monetary or other) employed in a purchase:
E.g multō aurō hanc aulam ēmī. “I bought this pot at the cost of much gold.”

The Ablative with Deponent Verbs

An instrumental ablative is used with utor, fruor, potior, fungor, uescor, and their compounds:
E.g hīs uerbīs ūsī sunt. “They employed these words.”
E.g mālunt ōtiō et pāce fruī. “They prefer to enjoy leisure and peace.”

A Great Printout for the Ablative can be found here.