Ciao Peter,
I'd be happy to help you understand the usage of "lo" in Italian sentences.
Here are some guidelines to address your questions:
⇨ "Lo" is used in Italian to refer to a specific object or idea. It can function as a direct object pronoun, replacing a masculine singular noun. While in English, we often omit the equivalent pronoun, in Italian, it is typically used.
⇨ The use of "lo" is not limited to specific verbs. It can be used with various verbs depending on the context and the presence of a direct object. Some common verbs that often accompany "lo" include "vedere" (to see), "sapere" (to know), "dire" (to say), and "ricordare" (to remember).
⇨ As a direct object pronoun, "lo" generally comes before the verb in Italian sentences. However, there are some cases where the word order may vary for emphasis or stylistic reasons.
Now let's examine your examples:
➙ "Non lo so" means "I don't know (it)" in English. The pronoun "lo" replaces the masculine singular noun referring to the thing or information you don't know.
➙ "Lo sai una cosa" translates to "Do you know something (it)." Again, the pronoun "lo" replaces the masculine singular noun and is used to refer to the specific thing being asked about.
➙ "Non me lo ricordo" means "I don't remember (it)" in English. Here, "lo" replaces the masculine singular noun representing the thing or fact you don't remember.
➙ "Karen non lo vuoi dire" translates to "Karen doesn't want to say (it)." The pronoun "lo" refers to a specific object or information that Karen doesn't want to disclose.
In each of these examples, "lo" is used to replace a specific object or idea, which is why it is necessary in Italian but may not be explicitly expressed in English.
Remember that the use of "lo" as a direct object pronoun is just one aspect of Italian grammar, and there may be additional contexts and nuances to explore. However, I hope this explanation clarifies the usage of "lo" in the examples you provided.
If you have any more questions or need further assistance, feel free to ask. Buon proseguimento! (Have a nice continuation!)