Conditional sentences (3, mixed conditionals)

1. How they are formed

Third conditional: if + Past Perfect, ... would have + V3
Mixed conditional (past → present): if + Past Perfect, ... would + V
Mixed conditional (present → past): if + Past Simple, ... would have + V3

2. When to use

Third conditional: regret and unreal past situations.
Mixed conditional: to connect past causes with present results, or present conditions with past results.

3. Examples

Third conditional (past regret):

If I had left earlier, I would have caught the train.

Mixed conditional (past → present result):

If I had studied medicine, I would be a doctor now.

Mixed conditional (present → past result):

If I were more attentive, I would have noticed the mistake yesterday.

4. Differences and notes

Third vs Mixed Conditionals

Third conditional stays in the past; mixed conditional connects different time references.

Choosing verb forms

Use Past Perfect in the if-clause for unreal past. Use would have + V3 for past result and would + V for present result.