Neither my English nor my Chinese is good.

That is the unfortunate truth. I tried really hard to improve my English. I can think in both languages and translate for almost any subjects between Chinese and English. Howevery I am not 100% comfortable with either languages. My Chinese is probably at 90% and my English is at 60% capacity of the native speakers.

I think my weaker performance in mastering languages is steming from being an engineer, as I don't practise reading or writing English much and don't use Chinese at all on my job.