Latin is a language of exceptions; the patterns that exist to form, for example, the conjugation of a verb cannot be relied on to conjugate verbs belonging to other conjugations. English speakers are used to this because English is also a language of exceptions.
Latin sentences, however, are constructed far differently than English sentences. English is largely an uninflected language in comparison to Latin. There is not a one-to-one relationship between a Latin sentence and its translation into English. Some teachers of the language take a “puzzle” approach to Latin and teach their students to think of Latin as a puzzle; you uncover a translation by considering one piece at a time.
Latin takes a lot of time to learn. Even the simplest of tasks such as conjugating a verb takes memorization and practice. Unfortunately, most Latin learning programs do not offer the amount of practice necessary to master a concept before moving on to another.
Self-learners of the language are particularly vulnerable to frustration because they do not have an expert on which to rely when questions pop up or difficulties arise in understanding a concept. There are a number of books out there to help, but sometimes you need an expert by your side to help you over those rough spots.
The closest resource the self-leaner has to having a teacher by his/her side is the Wheelock Latin program. Wheelock offer three main books that not only cover the language in an easy-to-learn manner, they afford the Latin student enough practice such that students fully learn a concept before moving on to the next topic.
For those interested in Wheelock’s Latin program, be sure to get the following books:
1) Wheelock’s Latin (6th edition) by Frederic M. Wheelock. revised by Richard A. LaFleur
2) Workbook for Wheelock’s Latin (3rd edition) by Paul T. Comeau and Richard A. LaFleur
3) Wheelock’s Latin Reader by Richard A. LaFleur
As an added bonus, consider:
1) A Comprehensive Guide to Wheelock’s Latin by Dale A. Grote
This one walks you through the tough stuff when Wheelock does not give quite enough instruction on a topic.