Using non-English words will make my password secure.

If an adversary has enough of an incentive and the resources to target you for your password to access your accounts, they will probably know quite a bit about you, including what language(s) you speak. When they (or someone they hire) attempts to brute-force your password, they will put words relevant to you in the word list they use to “guess” your password. This is likely to include words in your primary language and words particularly relevant to you, such as names of family members, locations (where you were born, where you’ve lived or travelled), and dates (e.g., your date of birth, when your child was born, when you were married).