In my view all four canonical Gospels were originally in Greek.
Mark was written first. Matthew and Luke were compiled from Mark and a lost Greek text ('Q' - which MIGHT be a translation of an Aramaic originalor include material from an Aramaic document). John is later still and probably uses material from Mark although it does not rely on direct copying.
Here is an example showing how John started in Aramaic and was translated into greek.
Where a word in the Aramaic may possibly be correctly translated
several ways it turns up in these different ways in various greek
manuscripts.
An example would be John 3:15
So that everyone who believes in Him not will perish.
The word translated here as "in him" may be translated 'in Him", "on
Him", "into him" or perhaps "through him".
All the Aramaic read the same but when it comes to the greek.
The following Greek manuscripts translate it "In Him": p75, B, W, 083
0113
The following translate it "On Him": p63vid, p66, A, L
And the following translate it "Into Him": S, K, Delta, Theta, Pi, Psi,
086, f1, f13, 28, 33, 565, 700, 892, 1010, 1241