Questions & Answers about Ta gruszka jest bardzo dobra.
Why is it ta and not ten or to?
Ta is the feminine form of the word for this. Because gruszka (pear) is a feminine noun (which you can usually tell because it ends in -a), the pointing word has to match its gender. If the word were masculine, like banan (banana), you would use ten banan, and for neuter, like jabłko (apple), you would use to jabłko.
Why is the adjective dobra in the nominative case here? I learned that jest takes the instrumental case!
This is a very common trap! When you use jest (is) followed only by an adjective, the adjective stays in the nominative (basic) case. So, we say Ta gruszka jest dobra. You only use the instrumental case if a noun follows the verb, for example: Ta gruszka jest dobrym owocem (This pear is a good fruit).
What is the dictionary form of dobra?
The dictionary form (which is the masculine singular form) is dobry. Here, it takes the -a ending to match the feminine noun gruszka. If you were describing a neuter noun, like an apple, it would be dobre jabłko.
Can I drop the word jest and use to instead?