There are ten grammar levels for the Grammar Based Lessons.  Our grammar levels are always revisable and we encourage your input in how to make them clearer and better defined.  Here are the current rough guidelines for the different grammar levels:

1. Level 1 -  set welcome/goodbye expressions, introduction phrases, be/do sentences and questions, this/that/these/those. basic singular/plural verb agreement.
2. Level 2 - Basic 3 word sentences, past tense, be/do/have sentences/questions with past.
3. Level 3 - future, basic comparison, comparative, basic wh-?s, can, irregular past verb forms.
4. Level 4 - Future tenses, complex wh-?s, prepositions, simple conjunctions, should, could, might.
5. Level 5 - Prepositions of time before/after/until/by/during/within/when, 1st conditional (if, unless), gerund vs. to infinitive.
6. Level 6 - the, a, an, some, any, one, ones, use(d) to, would, basic reported speech, would, complex inifinitive, complex conjuctions, determiners, passive voice.
7. Level 7 - restrictive/unrestrictive relative clauses (that, who, which, whose, where), unfulfilled past events (if I had ..., I would), complex future phrases, complex reported speech (back-shifting of verbs) , tag questions.
8. Level 8 - modal + have, ~thing (something, anything, everything), ~ever (whatever, whoever, whenever, however), it/wh- clauses
9. Level 9 - Discussion articles, methaphors, similes, phrasal verbs, subjunctive, inversion
10. Level 10 - written only english, old english, specific variations of english (singlish, Australian English), written expressions