Unfortunately
Use this like 'regrettably'. It's very similar to 'desafortunadamente' but can feel slightly more formal or express deeper regret.
Means 'by misfortune' or 'unluckily'. It's a very common and slightly less formal alternative to the words ending in '-mente'.
Translates to 'What a shame that...'. Use this to express sympathy or regret about a situation, often one that affects another person.
Unfortunately, I can't go to the party tonight.
Unfortunately, the bus already left.
I wanted to buy the car, but unfortunately, I don't have enough money.
What a shame that you can't come with us.
The phrases 'desafortunadamente', 'lamentablemente', and 'por desgracia' are standard and understood everywhere in the Spanish-speaking world.
In very casual, friendly conversation, you might hear 'qué mala onda que...' which means something like 'what a bummer that...'.
A very common colloquial expression is 'qué macana', which means 'what a bummer' or 'what a shame', used in the same way as 'qué lástima'.
While all forms are used, 'por desgracia' is particularly common in everyday speech. The other forms are perfectly normal as well.
Usage is standard. 'Qué pesar' is also a common alternative to 'qué lástima' to express sympathy or regret.
Using 'infortunadamente'. — While this word exists, it is extremely formal and almost never used in conversation. Stick to 'desafortunadamente' or 'lamentablemente' for a natural sound.
Saying 'por desafortunado' instead of 'desafortunadamente'. — Adverbs that describe how an action is done often end in '-mente' in Spanish, just like '-ly' in English. The correct form is 'desafortunadamente'.
Using the indicative after 'Qué lástima que'. For example: *'Qué lástima que no puedes venir.'* — This structure expresses a feeling or judgment about another fact, which requires the subjunctive mood. The correct sentence is 'Qué lástima que no puedas venir'.