Formal:
* 寂しい (sabishii): This is the most straightforward and direct way to express sadness and loneliness. It literally means "lonely," but it carries the weight of sadness as well. You can use it in a sentence like:
* 寂しいです。(Sabishii desu.) - "I feel lonely."
* 心が沈んでいる (kokoro ga shizunde iru): This translates to "My heart is sinking." It conveys a feeling of heavy sadness and loneliness.
* 心が沈んでいます。(Kokoro ga shizunde imasu.) - "My heart is sinking."
Informal:
* 寂しいなぁ (sabishii naa): This is a more casual way to express sadness and loneliness, often used among friends or family.
* 一人ぼっちで悲しい (hitori botchi de kanashii): This means "I'm alone and sad." It emphasizes the feeling of isolation.
* なんか、虚しい (nanka, munashii): This translates to "I feel empty." It can be used to express a deep sadness and loneliness, often stemming from a lack of purpose or meaning.
Adding Context:
To express your specific feelings, you can add context to the sentence. For example:
* 最近、寂しくて、よく泣いてしまいます (saikin, sabishikute, yoku naite shimaimasu): "Recently, I've been feeling lonely and I often cry."
* 誰かと話したいなぁ (dareka to hanasitai naa): "I wish I could talk to someone."
Remember that the best way to express your feelings depends on the context and the person you are talking to. You can choose the expression that best reflects your level of formality and the intensity of your feelings.