Today’s grammatical expression is “at best”, and we use it when we want to talk a person not being able to do something really well or within a certain time. We use “at best” to talk the highest level we think they are able to achieve. For example:
I don’t think I’ll win the race. At best, I’ll come in second place.
There’s no way we’ll be able to finish this project by May 5th. At best, we’ll finish it by May 8th.
I can’t make ten cakes by 5:00. I’ll be able to make seven of them at best.
I really doubt Steve will get an A in his chemistry class. I’d say he’ll get a B at best.
So, as you can see, we can put “at best” at the beginning of the second sentence or at the end of the second sentence. We always have a sentence at the beginning to explain the situation. We can use this expression to talk about ourselves or about other people who are not there. However, it’s very rude to say this to a person directly because it’s quite negative.