When you want to say opposite meaning of "be good at", just add "not" to "be good at".
I'm not good at English.
I’m not good at cooking.
Synonyms of be good at
be skilled at
to do something very well, especially for sports or art that need skill or ability.
He is skilled at basketball.
cut out for
to be the right to do something, usually used with negative sentences.
I soon realized that I wasn't cut out for that job.
Android App: English Buddy
One of important factors to learn English is to speak English. The app helps you speak and listen to English. In addition, you can create your own word list and test them. Here is the link to see more detail on Google Play.
● YURAGI(iPhone) ● YURAGI(Android) - You can listen to nature sounds such as rain, river, fire during your work, study or free moment between things. - YURAGI is subscription app including one week free trial but you can listen to four nature sounds for free. - Sample movie of YURAGI
● HONEYEATS(iPhone) - SImple food diary app - You can understand your eating habit, meal time and the app calculates total calories of the day for you.
