Translation of "let me know"

Question

I use the phrase "let me know" all the time in English. For example:

• Just let me know when you're free.
• Could you let me know whether you can come tomorrow?
• If you have any questions, just let me know.
• Let me know what you think.
• etc.

What options are there in Spanish for expressing "let me know," and how are they normally used?

Answer 1

In general it could be translated as either avísame or házmelo saber. For example:

• Just let me know when you're free. --> Avísame cuando estés libre.
• Could you let me know whether you can come tomorrow? --> ¿Me podrías avisar si puedes venir mañana?
• If you have any questions, just let me know. --> Si tienes alguna pregunta, házmelo saber or... avísame si tienes alguna pregunta or... si tienes alguna pregunta, avísame.
• Let me know what you think. --> Hazme saber qué opinas or... avísame qué opinas.

Personally, I prefer avísame. It's more concise.

Answer 2

I must agree that avísame is more concise, but at the same time I think it's too imperative. What I mean is that it could be seen as rude since you are giving an order. I would use podrías avisarme instead because it's more passive. It's the exact same difference that exists between Tell me this and Could you tell me this?.