I learn English everyday. I keep on reading, writing, speaking and listening. How can I know that I am making progress? Is there any quantitative standard?
- Using spaced repetition software such as Anki for learning vocabulary. After each session with Anki, you can see how far you got in the deck you have just reviewed. (I recommend creating your own decks instead of downloading random decks from the web. This makes sure that your Anki deck is relevant to your other learning materials.)
- Note: You can also use spaced repetition software to learn grammar but it will be less obvious what you will be quantifying here. If you use cloze cards to practise grammatical constructions (as described in my other answer), you will merely be quantifying the number of sentences you have reviewed, not the number of grammatical features you have mastered.
- If you want to go super-quantitative on vocabulary learning, you can use SAFMEDS, which stands for "Say All Fast a Minute Every Day Shuffled". Progress is then measured using "acceleration charts".
- Tracking how much time you spend learning the language. (You can track the time spent on reading, writing, speaking and listening separately, or just track time spent on language learning globally. You can also track how long your current "learning streak" is.) Some people use a bullet journal for this. See for example 10 Ways to use a Bullet Journal to Improve Language Learning (21.02.2017).
- Rereading texts a few weeks after you've learnt their vocabulary and grammar. This will enable you to see whether you still struggle with the language of that text or not and thereby notice your progress. This is obviously less quantifiable than tracking time or words, unless you want to count texts.
- During conversations, try to be attentive to the frequency of quesions to repeat things etc, i.e. questions that indicate that the conversation is not running smoothly for linguistic reasons. After the conversation, try to figure out whether such interruptions were due to deficiencies in vocabulary, grammar, pronunciation or something else. You can write these down in a journal and then set a goal to master these difficulties. You can then later check these items off as things you have learnt.
- When you read a text you haven't seen before, you can track how many times you stop to look up a word. (You can leave that text alone for a few weeks and check again; see number 4.)
- The above are low-level measurements. For a high-level measurement, you can download the CEFR self-assessment grid and see where you are on a scale going from A1 to C2. (The CEFR is the Common European Framework of Reference for Languages, developed on behalf of the Council of Europe. In addition to the self-assessment grid, there is also more detailed information about each of the six levels. For a more objective assessment of your level, you should actually take a test.)