Meaning
Literally 'I say', but chiefly used as an emphatic discourse opener — to introduce a statement, express astonishment, or add weight to what follows. 'Mi seh di place did pack!' means I'm telling you, the place was packed, with 'mi seh' throwing emphasis and feeling onto the words to come rather than reporting any actual speech. It functions like 'I'm telling you' or 'let me tell you', and it is a very common way to launch into a story or an exclamation, drawing the listener in and marking that what follows is worth hearing.
Examples
-
Mi seh di party ram last night!
I'm telling you, the party was packed last night!
Here 'mi seh' is pure emphasis, not reporting speech; 'ram' means crowded.
-
Mi seh to him fi come early.
I told him to come early.
This is the literal reporting use; 'seh' also works as a complementiser meaning 'that'.
-
Mi seh, di heat today too much!
I swear, the heat today is too much!
Standalone exclamation of exasperation at the start of a sentence.
Origin
From English 'me say' / 'I say'. The word 'seh' also serves the West African-influenced grammatical role of a complementiser (like Akan/Twi patterns), functioning as 'that' after verbs of speaking and thinking.
How it’s used
Extremely common in casual speech. As an emphatic opener it signals the speaker is about to share something notable. Foreigners often mistake every 'seh' for the verb 'say', missing its grammatical role as 'that'.