The following sentences are given as correct examples regarding Sequence of tense
I miss my dad more than I missed anything.
I miss my dad more than I will miss anything.
I can't really understand the grammer behind these 2 sentences, especially the second sentence sounds completely wrong to me.
And the rule on the web site, which didn't make sense to me, says: Usually, no present form is allowed in the subordinate clause if the principal clause is in past tense. But if the subordinate clause starts with “than”, then the subordinate clause can be in any tense.
So, I am not native speaker and I wanted to ask. Are these sentences grammatically correct? If yes, how can you be so sure about the future? How do you know that you won't miss anyone more than him in the future?