1. Special constructions
1.1. Type 2
1.1.1. They emphasize improbability
1.1.2. IF-clause: should + inversion
1.1.3. MAIN: conditional or imperative
1.2. If only/I wish...
2. Basic structure
2.1. They consist of a MAIN CLAUSE and an IF-CLAUE
2.2. The IF-clause expresses the condition itself
2.2.1. It is normally introduced by the conjunction "if"
2.2.2. Other conjunctions may be used:
2.2.2.1. as long as
2.2.2.2. provided/providing
2.2.2.3. unless
2.2.2.3.1. Meaning: "if not"
2.2.2.4. in case
2.2.2.4.1. not really a conditional
2.3. The main clause expresses the result of the condition
2.4. Types
2.4.1. Type Zero
2.4.1.1. General or universal conditions
2.4.1.2. IF-clause: if + present simple
2.4.1.3. MAIN: present simple
2.4.2. Type One
2.4.2.1. Probable conditions
2.4.2.2. IF-clause: if + present simple
2.4.2.3. MAIN: future
2.4.3. Type Three
2.4.3.1. Conditions in the past (impossible)
2.4.3.2. IF-clause: if + past perfect
2.4.3.3. MAIN: conditional perfect
2.4.4. Type Two
2.4.4.1. Unreal or improbable
2.4.4.2. IF-clause: if + past simple
2.4.4.3. MAIN:conditional