Sometimes you see people recommending Cure Dolly as a grammar resource. I tried going through it, and here's my takeaway.
- The grammar explanations are a complete joke. I'm not saying that any competitors are perfectly correct either because they rely on English to describe Japanese, but Cure Dolly is on a different level.
- Cure Dolly is creepy. Not everyone's going to have enough willpower to sit through its voice.
- It is long. Most of the content is in video format. I'm not a big fan of videos. Reading a written grammar guide is going to be more efficient. The grammar guide should be concise and have natural example sentences with translations for each grammar point it explains. Example sentences are more important than explanations.
In order to understand grammar you have to understand it in Japanese. When a guide uses English building blocks to make a model that resembles the Japanese grammar, there's a limit on how accurate the explanations can be.
On this site we recommend reading one of the recommended grammar guides to acquire a rough understanding of what each of the most common grammar patterns means in order to comprehend more of your input. We don't concern ourselves with how to apply the rules to produce Japanese, this is something that comes naturally with immersion. Later, when you become fluent, we advise learning Japanese grammar in Japanese, using resources meant for native speakers.