I can tell that English is the easiest language I ever learned.
Between these languages (that I learned or I’m learning): French, German, Japanese, Spanish, Finnish and Arabic- is the hardest although is my mother tongue- I find English always the easiest ,especially its grammar.
So if I order these languages from the hardest to the easiest for me, it would be:
1-Arabic
2-Finnish
3-japanese
4-french.
5-german
6- Spanish.