- purpose
Purpose clauses are introduced by ut or ne with the subjunctive, and are the principal way that Latin expresses things like "He lives to eat", "He lives in order that he may eat", "he lives so that he can eat" and so forth. The English construction that most closely matches the Latin here is to translate the "ut" as "so that" or "in order that" and the subjunctive as "may" or "might". The only tenses of the subjunctive you ever meet in a purpose clause are the present and imperfect, so you can forget entirely about the perfect and pluperfect subjunctives here.

- result
Result clauses look superficially similar, in that they're also introduced with ut, but there are a number of important differences:
- Result clauses usually (though not invariably) include a "so-word" like tam (so), adeo (so much, to such an extent), or tantus (so great) in the main clause "setting up" the result. ("This is so easy that I can understand it without the use of mind-altering drugs.")
- Result clauses don't use ne as the negative of ut. They use ut with an ordinary non instead.
- Result clauses use all tenses of the subjunctive, and are one of the few constructions to use the perfect subjunctive a lot. They even sometimes try to use a future subjunctive (which doesn't exist as such) by cobbling one together out of the future participle + sum. Remember: translate the subjunctive in result clauses as the equivalent tense of the indicative.

- In those rare cases where none of the above helps, the sense will give a clear guide - it just won't make (logical) sense if you translate it as a purpose clause.
- cum
The conjunction cum is used in a bewildering variety of senses, though not as bewildering as the way they're set out in the book. There are really just three main ways to translate it: when, since, and although, and here's a little visual guide to how to tell which translation you need.

- When cum takes the indicative, translate it as "when".
- When cum takes the subjunctive:
- if the verb is in a so-called primary tense (see the diagram), translate it as "since";
- if this doesn't make sense, it must mean "although".
- if the verb is in a historic tense, see whether the sense works better with "when" or "since";
- if neither, try "although".