Grammar is for most people the least interesting part of learning a language and especially German grammar has a reputation to be particularly boring.
Therefore, wait to study grammar in details until later in your learning process. Most textbooks will slowly introduce you to grammar, when you start to need it.
In most situations, you will get your message across, although you have the wrong word order, incorrect preposition, or use a mistaken grammatical tense.
… but you end up sounding like a German Yoda from Star Wars, so at some point you need to pick it up.
It is certainly all right to sound like Yoda in the beginning, and not knowing the grammatical rules should never keep you from trying to speak German.
Besides learning 100% perfect grammar in any foreign language is a mission impossible. There is always an irregular verb or a certain rule you keep forgetting.
All right, German grammar is difficult, but how do I learn it?
Some decide to spend almost no time with grammar books, and just pick it up along the way. I learnt English and Swedish this way, but unlike these two languages, the grammatical structure in my native language Danish is very different from German.
Consequently, I had to develop another approach to the German grammar, which can be divided into three steps.
1) Learn a handful of grammar rules, and be realistic about how many you can remember and write them down on a piece of paper. For me it’s realistic to remember between two and five rules.
2) Watch a film or a TV show and try to spot the grammar rules you have recently learned.
3) Start using the rules you have learned when you speak with your Free German Tutor and don’t be afraid to show off your newly gained skills.
Other Sources and Interactive material for Learning Grammar:
Endless collection of exercises. Particularly for grammar and the difficult German word order.
Livemocha has everything. How the grammar works, exercises, and plenty of people willing to help and correct you.
Die Goethe Institute has a lot of learning sources. These sources focus heavily on grammar.
Strategies for Learning Grammar
Some strategies and inspiration for learning grammar.
Youtube | German Grammar
Search for German Grammar on Youtube, and you’ll get a lot of very useful videos.
Helpful introduction to German grammar and a good deal of exercises.
Best German Web Sites
Lots of links, including grammar websites.
BBC Language Notes
Grammar notes from BBC.
10 lessons mainly about Grammar.
German course in 11 lessons, which includes grammar as well.
Look under structure practice and you’ll some grammar games to play.
Lots of stuff and much of it is grammar.