mixed conditional if clause

Question

Sentence a )

''If you went swimming this morning, you can’t go swimming again tomorrow.''

The sentence above is mixed conditional if clause, and in the website first part of the sentence is said to refer to past tense .

but in my opinion if I want to refer to past tense in if clause I should use ''had gone swimming''.

Sentence b)

''If you had gone swimming this morning,you can't go swimming again tomorrow.''

if I want to refer to past tense in first part of the if clause, is sentence a or sentence b ok?

Answer 1

A conditional clause of the form if you had done is usually a counterfactual, and its consequent is normally given in a subjunctive or conditional mood: “…you could not…” or “…you would not be able to go swimming again tomorrow.” (English can is a defective verb; for its missing forms we have to paraphrase.)

Answer 2

Sentence b definitely sounds wrong. You would use the past perfect tense only if talking about something prior to another past event, like "If you had gone swimming before you ate breakfast this morning,..." You could also have the second (more recent) past event in the consequent, for example, "If you had gone swimming this morning, you couldn't have gone swimming again this afternoon." I think sentence a sounds ok.