tell me the use ?

[Mr_jim]

whether to these expression...?
plz, elaborate with examples:
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1> how <u>can</u> I know that?
2>How <u>could </u>I know that?
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[Rusty]

1> how can I know that?
2>How could I know that?
(The concept is the same. The construction of the sentences and their answers differ.
Example: How can I know that? You can know (learn/find out) the facts by reading the reports.
How could I know that? You could know /learn/find out) if you read/were to read the reports. Note: "if you read" -- read is past tense, pronounced red. "Were to read" -- read is present tense, pronounced reed).