[Unique.s]

What is the difference in the meaning between following sentences:

1. John was to have picked strawberries yesterday but the downpour made the field too muddy.
2. John was to pick strawberries yesterday but the downpour made the field too muddy.
(Source: modified example from BBC
Learning English | BBC World Service)

I've read in Learn English BBC that the form "was to" and "was to have" is used for past plan which wasn't fulfilled. But what I haven't understood is that these forms look similar to me. I'm in a dilemma which one (*was to*, or *was to have*) is used for past and which one is for unfullfilled past.

So, what are the differences between the constructions

- *was/were to* + infinitive
and
- *was/were to have* + past participle.

Please make it clear with examples ?
I would appreciate your helpfull answer.

[susan53]

No difference in meaning. "was to" already tells you that a past event is being described, so the perfect infinitive "have picked" is redundant. It adds nothing to the meaning that wasn't already indicated. So the simple infinitive is also possible and the meaning remains clear.

Compare this with eg:

He may go on Saturday
He may have gone on Saturday

Here the only indication of past time carried by the verb is in the perfect infinitive, so it is obligatory - otherwise "on Saturday" is interpreted as "next saturday" rather than "last Saturday"