Usage of past tense to mean future or present

[Jraou]

Hey,

How is it that we use past tense when we mean future or present in sentences like:

" I'd prefer it if you left number 3 until last."
" I'd rather you didn't use more than 150 words in your summary."

[Molly]

The past tense does not only refer to past time.

The past simple, for example, is used for:

TIME - I lived in London during the sixties.
"POLITENESS" - Did you want to try that jacket on, madam?
POSSIBILTY - Could you come and see me tomorrow? I have something to tell you.

Your examples would fit into the "politeness" category. Making suggestions, is often accompanied by the past tense.

[Alan]

Hi Jraou,

This isn't really a past tense but more an example of the 'unreal past' or subjunctive. In English the past indicative and subjunctive look the same (except in the case of the verb 'be' ). Possibly this can be explained as follows:

[Molly]

[MrPedantic]

The subjunctive mood in the first sentence may be easier to perceive in this approximate alternative:

1. I'd prefer it if you were to leave number 3 until last.

MrP