Key Concepts:
In English grammar, the words 'weep' and 'cry' are often used interchangeably to express sadness or emotional distress. However, there are subtle differences in their usage.

Usage Examples:
1. She wept uncontrollably when she heard the news.
उसने खबर सुनते ही बिना संयम रखे रो पड़ी।

2. The baby cried all night because she was hungry.
बच्ची रात भर रोती रही क्योंकि उसे भूख लगी थी।

3. He wept tears of joy when he won the competition.
उसने प्रतियोगिता जीतने पर खुशी के आंसू बहाए।

4. The little girl cried when she fell down and hurt her knee.
छोटी सी लड़की गिरकर अपनी टखने पर चोट लगने पर रो पड़ी।

Key Mistakes:
One common mistake is using 'weep' instead of 'cry' in everyday conversations. For example, saying "I wept during the sad movie" instead of "I cried during the sad movie." Another mistake is using 'cry' instead of 'weep' when referring to shedding tears of joy or relief. For instance, saying "She cried when she got the good news" instead of "She wept when she got the good news."

In conclusion, while 'weep' and 'cry' are often used interchangeably, it is important to understand their subtle differences in usage. By using these words correctly, you can effectively express your emotions in English.