i saw the advertisement .......... your Chinese classes yesterday
- What should i write in? About, for or of
I searched on the internet and it only showed advertisement for which means show its(something after the "for") goodeffects
If you say that an example of something is an advertisement for that thing in general, you mean that it shows how good that thing is.
[mainly British] The England team were a poor advertisement for European football tonight. (Collins dictionary)
An advertisement you see in a newspaper, for example, is one where something is offered for sale.
If you want to sell a bicycle in a newspapers, you might say I'd like to place an advert for a cycle. Here about is not possible, although it fits other situations (e.g. What is the advertisement about/for?).