John 3:11

ἀμὴν ἀμὴν λέγω σοι ὅτι ὃ οἴδαμεν λαλοῦμεν καὶ ὃ ἑωράκαμεν μαρτυροῦμεν, καὶ τὴν μαρτυρίαν ἡμῶν οὐ λαμβάνετε

Truly truly I say to you, that which we have known we speak and that which we have seen we testify and our testimony you all do not receive


 * οἴδαμεν and ἑωράκαμεν are perfect active indicative 1P pl. Makes sense, as it is things that have happened but which have continuing relevance
 * λαλοῦμεν and μαρτυροῦμεν are present active indicative 1P pl.
 * Why is Jesus using 1P plural here?
 * Also notice λέγω σοι - say to you 2P sg. but λαμβάνετε is 2P pl.