What are the best grammar activities that students need to practice more often to learn faster?

      Since you haven't mentioned their level, I'll start with absolute zero beginners. You can start with flash cards that have pics and words only in English. Ex: A for ant and B for ball etc. First you start only with nouns. Make sure that they can tell the words if they see the letters of the alphabet that you have introduced. Then, you can start with "what is this ?" and "what are these ?"At this point, you have introduced them to plural forms of nouns.

      Then you can introduce pronouns, if possible with free flash cards from Tes.com. It's a great site for jobs too. Ex: It is a cat. They are cats. He is a boy.They are boys,etc.Use only simple who  and what questions.

       Any basic grammar book will tell you how to proceed further using graded beginners' exercises. If I were to teach advanced TESOL students, I would use the contextual method : No grammatical terms would be used. I would tell a simple story in about 200 words like 'The hare and the tortoise'.Using words from the story I would drill them on singular, plural, gender, synonyms, antonyms and exceptions.This enhances their vocab.

       You need to use props in the classroom and the students themselves for your exercises. Innovations, gestures and activities make your teaching effective and interesting.

You can try:

1. circling action verbs in a sentence, categorize them into present, past, or future tense, and then take turns changing the tense of the verbs;

2.find the nouns and replace with other nouns;

3. make lists of synonyms and/or antonyms and use them interchangeably;

4. differentiation between sentences written in active voice vs passive voice

sorry i'm not expert on these field

Agree with your specialties answers. Thanks. 

Grammar is something which needs frequent practice to keep on track.

Practicing Tenses is a highly recommended way to learn English faster.

Still it's not enough to satisfy all. Some people are better in Tenses but are weak in other parts of grammar. So each learner has to analyze his own deficiencies to practice it more frequently.

Thanks

Sorry , i have no idea

Apologized for the answer, I do not know the answer Leave for the professionals.

There is one activity that I find enjoyable and students won't get bored while trying it:

On each  sticky notes write one  word

then make students each pick two sticky notes

Ask them to write sentences using those words while defining what verb tense to use. 

It is a funny game and the results are too funny.

For instance:  Use football and horse in a sentence:

So the sentence would come out as follows : A man was attacked by a horse while watching  football at home. 

If question was for Arabic language i'll answer

But I haven't knowledge of English

The following things can help your students to learn English faster.

1. Tenses

2. Structures

3. Phrasal verbs

4. Contextual meanings

5. Idioms

Francis Panikulam has answered the question very well