One of the things from I love Lucy that stand out for me, is the fact they included speaking another language, español in this case, as a recurrent situation. The fact that Ricky Ricardo is Cuban means that there's a cultural barrier between him and Lucy. But I like the way they approached to these barriers throughout the series: it was a problem for both of them, not just for one of them; it meant that Lucy wasn't able to speak a second language and that she didn't know much about her husband's country, and it meant that Ricky had to struggle to improve his English.
This is a common problem in a lot of American movies: the portray of different cultures is based on prejudice, stereotype and lack of research. Why I don't mind this in the case of I love Lucy? Because the screenwriters decided to make it evident by exaggerating the elements and turning it into something positive by showing that Lucy is making an effort to help her foreign husband.
Another of my favorite scenes is when Lucy meets her mother-in-law and then when she tries to explain her what they're having for supper. Here, both women are in the same situation, trying to help each other, because both have a lack of knowledge: